A History of Pokémon through the Internal list – MissingNo. Descriptions

Finally, we arrive at one of the most speculative and experimental parts of researching Generation I. In this article we will summarize the MissingNo. patterns and also list a bunch of hypotheses for each, from most to least plausible.

Another general shared pattern among every MissingNo. is redundancy, so we might expect that some monsters had been deleted because they were too similar to others. We can also assume the existence of several cut evolutionary relatives (about one fourth according to our estimation), since, as Nishida and Nishino stated in the 2018 interview with Famiuri, when they had to make the final cut, they ultimately favored diversity above long evolution lines. Enjoy!

We strongly suggest reading the whole research starting from the intro, as it will equip you with the correct context to understand the identifications.

INTRO P1 P2 P3 P4 P5


P1a MissingNo. speculative description: Designed by Ken Sugimori, No clear typing, single stage, Kaiju and dinosaur-like or typical RPG monster, helpful monster, Capumon.

Given the variety of inspirations and the likely possibility of multiple reworkings of the first 37 “Capumon,” we can’t exclude that one of the three MissingNo. could be Gyaasu/Gyaoon (or possibly a more developed proto-Tyranitar) – or even the elusive scrapped “O” (Since even Spearow, who was crossed out in the Tajiri manga poll, still ended up being in the final 151).

The same ambiguity, however, might also lead us to think that neither Gyaoon nor “O” made the 190 cut and became fully lost Pokémon instead. Another explanation for Gyarados’ absence from the P1 documentation might be, in fact, that Gyaoon was actually reworked into it, as some facial features and even the name might suggest a relationship or inspiration connecting the two. This hinges on the fact that Rhydon was moved from index spot 000 to spot 001, booting its original inhabitant out. Whether Gyaoon was moved someplace else or removed completely, and exactly when this switch happened, remains a mystery.

As you can see, it’s worth speculating about who the three P1 MissingNo. could be, other than Gyaoon or “O”.

The first MissingNo. on the list is  MissingNo. 021. In the final release, this slot is infamously occupied by Mew, although we know from several interviews with its creator, Shigeki Morimoto, that it was designed and put into the game after the debugging, implying it was coded in the very first slot available, and it replaced a former MissingNo.

MNo. 021 is placed between Arcanine and Gyarados, both of which seem to be based off legendary Chinese creatures. In this regard, Capsule Monsters refers to a particular monster category called “Mirage Monsters” (幻のモンスターMaboroshi no monsutā), a predecessor to the concept of mythicals and legendaries. (Ironically, Mew is often described as a “Mirage Pokémon” (幻のポケモン Maboroshi no pokémon) in promotional materials, but its later inclusion disconnects it from the original definition anyway.) 

Arcanine is infamously referred to as “Legendary” in the Pokédex, and it was placed among the legendary birds in the anime and other Pokémon related media. Gyarados is less obvious, but its high base stat total and lore make it into another candidate for an early legendary Pokémon. Assuming that these two were originally coded in Period 1, perhaps they had been designed with this “mirage category” in mind, and MNo. 021 might have been designed in the same vein, although we must acknowledge that Period 1 doesn’t always follow a reliable pattern.

There are a couple of possible inspirations that Game Freak could’ve used to design these monsters into a specific group of elusive, powerful creatures. Present in the Chinese mythology are four monsters which symbolize four cardinal directions, four of the five elements, and so on. These are (as called in Japanese): Genbu, a black turtle; Byakko, a white tiger; Suzaku, a red bird; and Seiryu, a blue dragon. This quartet is also present in Sa.Ga. (aka Final Fantasy Legend),  a game that heavily influenced the first Pokémon builds.

The Four fiends in the official art for the 1989 “Final Fantasy Legend” (魔界塔士, Makai Toushi Sa·Ga)

If these were truly an inspiration for them, then we could include Lapras, Blastoise or another lost Capumon as an interpretation of Genbu, Arcanine as Byakko, Gyarados as Seiryu, which would leave us with Suzaku – a red bird.

Different possible inspirations include another legendary Chinese group: Dragon, Shisa, Phoenix or a similar Biblical trio: Behemoth of the earth, Leviathan of the seas, Ziz of the skies (later inspired Groudon, Kyogre, and Rayquaza). In any case, the pattern – if present – might lead us to think that 021 was an avian creature (mind that we know for sure that Ho-oh wasn’t planned for Generation I).

Maybe an early “mirage” bird might’ve inspired the final legendary trio. Speculatively, in a first P2 draft that would have ended at 073, Moltres might have been added during a draft of P2 to complete the P1 Chinese trio/quartet. It then would have been expanded into the three elemental birds, taking away Arcanine and Gyarados’ legendary status in the process.

MissingNo. 031 and 032 might fall into one of the main patterns of P1, thus being inspired either by Kaiju, bugs, or other typical RPG creatures.

There is also the route of exploring missing default base cries in the final games, which could be vestiges either of completely lost Pokémon or dummied-out MissingNo.

Apart from the already solved mysteries (0x06 Voltorb and 0x07 Gengar are exceptions; 0x08 was Ivysaur’s, 0x0E was Clefairy’s, 0x0F Gyarth’s), we’re left with three missing default cries: 0x20, 0x21, 0x23, and four mysterious default base cries inherited by Pokémon added in the later stages of development (assigned to Pokémon beyond ID 037, not counting Starmie 0x1E, since it probably inherited Staryu’s original cry). These are 0x1D, inherited by MissingNo. 181; 0x22, inherited by Rattata; 0x24, inherited by Graveler; and 0x25, inherited by Ponyta.

Why are there 38 default base cries and just 37 P1 Pokémon, then? It might be because the initial index went from 0 to 37, and one original Capumon disappeared seamlessly as a result of the earlier popularity polls. Alternatively, P1 Capumon have always been 37 and one spare base cry was originally assigned to Graveler, one of the first P2 Pokémon, and the current final user of default 0x24 (and the first P2 Pokémon instead of Kadabra, according to the Tajiri manga sheet).

It would be tempting to assign the missing base cries to the MissingNo. and the inherited ones to the other lost Pokémon, but we can’t really make these assumptions. For example, had Rhyhorn been a MissingNo. we would have put its cry among the inherited ones (it’s the same as Charizard’s) instead of the missing ones.

Overall the three P1a MissingNo. identities might be interchangeable; it is uncertain whether MNo. 031 and 032 are a part of P1a or rather P1b – in which case, they would be most likely a later addition, thus fitting into an unpredictable area of the list.


P2a MissingNo. speculative description: Designed by Sugimori, Morimoto, or Fujiwara. Clear typing single stage, elemental bipedal embodiments and battle archetypes, Yokai and folklore inspired. Probably Ice, Flying, Grass or Normal type.

One of these two MissingNo., either 050 or 052 as we can’t be completely sure, is misplaced or absent from the Tajiri manga charts for unknown reasons.

The 2a Pattern seems to imply that MissingNo. 050 and MissingNo. 052  used to be two more Yokai elemental bipedals like Drowzee (Baku), Golem (Golem), Magmar (Karura) and Electabuzz (Oni), and, by process of elimination, they could be Ice, Flying, Grass or  Normal,  (perhaps even Bird type!) which were all quite scarce typings during P2a.

To be fair, we’ve already seen how Fearow could be the missing 2a Flying Pokémon (or Bird since we don’t know if those types coexisted or one replaced the other) and the Grass and Normal Yokai status could’ve been retroactively given to Lickitung (Akaname) and Exeggutor (Jinmenju) at least pattern-wise and for battle testing purposes. Of course, we all know the Ice Yokai became Jynx in the final release, which incarnated the Yamanba or even the Yuki Onna (or even an Opera singer assuming she was originally envisioned as an addition to P2a). Perhaps MNo. 050 and MNo. 052 were deemed somehow redundant and scrapped in favor of those Pokémon?

Still, the Ice Yokai identification seems to be endorsed also by the internal move ID list. Some of the earliest moves programmed are, in fact, Fire Punch, Thunder Punch, and Ice Punch, two of which are the semi-signature moves of Magmar and Electabuzz. Since Jynx might’ve been added a bit later to the list, we can assume Ice Punch to have been initially given to our missing Ice Yokai, and only later became Jynx’ signature move. The lack of Ice types in P2a seems a bit odd, seeing how ice-electric-fire is a constant elemental triad for Game Freak and for JRPGs in general.

For speculation’s sake, we could also see Mega Punch as a hint, again, at a Normal yokai, and the inclusion of Pay Day (Meowth’s signature move) among the “punches” might hint at yet another – overwritten – signature move. Taking in consideration that the 1992 poll testimony tells us that Meowth was a later P2 addition, it’s too early for this list to parallel Meowth. Could Pay Day have replaced another “punch” or another signature move?

Identifying 050 and 052 with proto-Magby and proto-Elekid would make Electabuzz and Magmar very unique within P2, as none of the Pokémon in this period were originally intended to evolve. A way to justify those two pre-evolutions in the P2a list would be a later amendment that overwrote the original dwellers of those slots, thus turning the original elemental Yokai identities from MissingNo. into completely lost Pokémon.


P2b MissingNo. speculative description: Elemental – meant to be a single stage, ecosystem real-life animal-inspired fauna with a wacky twist, not meant to be rare Pokémon, but to populate a specific environment. Evolving in P4a if an evolution was planned, balanced types. By elimination, probably a Fire or Rock type.

MissingNo. 063 is certainly present on the Manga poll sheet, but unfortunately completely obscured. If Crocky does begin a subpattern of comedic monsters, most likely designed by Shigeki Morimoto, then 063 would also share this characteristic and maybe have Rock or Fire type, since those are absent in this period.

MissingNo. 069 is sadly omitted or misplaced in the Manga poll sheet. Its cry is an exact duplicate of Zubat’s (or rather it would seem that Zubat inherited MNo. 069’s cry). This could even mean there was a connection between the two, which is reinforced by the odd occurrence of Zubat in Period 3b. This could suggest that Zubat was a pre-evolution of an unknown Pokémon at that point – either that, or Zubat is one of the true rare exceptions in the sequence.

Just like how Pokémon similar to Venonat and Doduo were created to populate the routes, we can assume Crocky, Deer, Elephant, Cactus, and Jagg served the same purpose: enriching the pre-existing environment.

Cactus fulfills the missing “Grass-type realistic common fauna Pokémon” prediction. It’s also the first MissingNo. listed to have a cry, shared with small, spiky monsters like Nidoran and the desert-dwelling Sandshrew family. 

By the same process of elimination, we notice that the Fire type is still scarce in Period 2b (even counting Dragonite as one as we previously speculated in the P2 article). Could a Fire-type lurk behind one of the undiscovered P2b MissingNo.?We must also note that many MissingNo. could appear in the final list with a newer, revised design. Of note are Seel and Barunda, which seemingly had more than one design throughout their development – Seel was heavily revamped, while Barunda’s design had (A) appended to the end of its name in the 1994 poll, implying that other designs existed simultaneously for it. This is especially true for the ones marked with a triangle, like Crocky, Elephant, and Deer. Their revisions could have looked similar to their closest Gen 2 conceptual relatives. Anyone up for caveman Crocky – I mean, Croconaw?

PERIOD 2d MISSINGNO. (079 – 080 – 081)

P2d MissingNo. speculative description: Tests, gimmicks, and miscellaneous additions to the previous P2 patterns.

The Tajiri manga hasn’t revealed the identities of MissingNo. 079 and MissingNo. 080, and the non-uniform nature of this pattern leaves few features to go off of. They might have been small, gimmicky Pokemon. MNo. 079 shares a cry with the Rattata line, so maybe it was a rodent or another small animal?

MissingNo. 069 MissingNo. 079 MissingNo. 081


P3a MissingNo. speculative description: designed mainly by Nishida, but Sugimori, Morimoto and Fujiwara were also working on the project. Clear typing, elemental fauna with two-stage lines. Possibly meant to evolve by stone. The later placement of the Grass stone in the item ID list might infer that a Grass type line, albeit being missing, is less likely to appear than expected.

One thing to note is that P3a Pokémon resemble real-life animals with a cute elemental twist. This could hint at some features MissingNo. 086 and MissingNo. 087 would have.
Grass lines are, again, missing, but that might be due to the absence of the Leaf Stone. Seems suspicious nonetheless.

Further proof that MissingNo. 086-087 and 094-095 are in fact two 2-stage evolution lines is that MissingNo. 094 has the base cry 0x0F that is also used for MissingNo. 095 with a lower pitch. This suggests that they are related.

MissingNo. 094

MissingNo. 095

This base cry is also shared with the Bulbasaur line, Dratini line, and Pikachu and possibly hints at a lizard or amphibian, the only exception being Pikachu, of course.

Those two pairs might ultimately also add two stages to a 2b Pokémon, just like Dratini and Dragonair are related to P2b’s Dragonite.

We apprehend from Nishida’s 2018 interview that many P3 Pokémon were originally intended to have three stages, but one stage was eventually scrapped from most of the lines, just like Gorochu.

We can briefly speculate about who went missing before the 190 cut thanks to the lost Pokémon in the 1997 Gold Demo.  Mikon (Vulpix’ unused pre-evo) was most likely a candidate, as Vulpix’ Blue Pokédex entry even hints at its lost pre-evolution and also Kingdra might have been considered during this period. There’s a slight chance (but sadly no definitive proof) that some of these scrapped evolutions were re-coded elsewhere in the ID list, most likely in P5.


P4a MissingNo. speculative description: 2nd stage Evolutions of P2b Pokémon.

In the first part of Period 4a (ID 115-122), the creators planned to evolve exclusively P2b Pokémon. This choice is particularly interesting because some of those missing Pokémon are likely to be evolutions of Pokémon from the 057-070 range, including the MissingNo. whose identities were revealed in the Tajiri manga. If we must choose among them who is more likely to get an evolution, we may assume that slots 115, 121 and 122 might have hosted Crocky’s second stage, supposedly part of an evolutionary line that was cut altogether.

Considering modular Pokémon like Magneton, Diglett, Doduo, and Koffing are all in the same P2b range and all got a relative eventually, the same might go for Cactus (either in P4 or in P5 like Magneton).

Even Farfetch’d might have had its second stage in this range, the only counterargument being that its sprite hasn’t been downscaled like the ones of the other 2b Pokémon that eventually got an evolution. However, its bigger sprite could’ve been restored after its hypothetical evolution was cut, or just never downscaled at all (even if it would be quite an exception, since even Clefairy’s sprite was downscaled for apparently no reason, being already smaller in comparison to Clefable’s sprite).

There may also be an evolution to whatever MissingNo. 063 and 069 were (assuming that Zubat is actually an exception). Moreover, MissingNo. 121 and 122 could also be related to each other, perhaps forming a three-stage line with a Period 2b Pokemon, even if that doesn’t seem to be the trend according to the remaining monsters.

Design-wise, less likely candidates to get an evolution are Deer, Tauros, “Elephant” and Jagg, as it’s more likely that they would have gotten a pre-evolution instead, and those were very rare during Period 4 (they mostly appear together with another form, like Bulbasaur and Venusaur; the lone pre-evolution of P4 is Magikarp).

P4a MissingNo. speculative description: Evolutions of P2a Pokémon.

At (ID 126-130, Machamp – Golbat), it’s now the turn of Period 2a Pokemon to evolve: Machamp, Golduck, and Hypno all evolve from P2a Pokemon, even following the same order as their pre-evolutions, and Missingno 127 (with a modified Rhydon base cry) should also follow this pattern. 

Having inspected the special case of Mr. Mime, we think its evolution could have been heresince it would both follow the order and match the evidence in its movepool that endorses the theory of a scrapped relative:

  • Mr. Mime’s final Japanese name, “Barrierd,” is absent from the 1993 poll documents, and we already discussed the possibility of the mysterious Baririina being in its place, which is pretty much confirmed to be a name related to Mr. Mime, thanks to the 1997 Spaceworld Demo.
  • There’s a curious redundancy in Mr. Mime’s moveset: it learns Confusion both at level 1 and level 15. Duplicate moves in a level-up set are a usual sign of an evolved form. This fact, as well as Mr. Mime’s sprite not fully matching the dots in the slot where it is supposed to be, makes us think that 042 was originally occupied by another form, and Mr. Mime as we know it was added later and coexisted with its relative. As a counter-argument, some Pokémon do have moves learned multiple times at different levels, such as Mewtwo learning Psychic at level 1 and at level 66.

The other likely options for 127 are proto-Blissey and proto-Hitmontop. MissingNo. 127‘s cry,  which is a variation of Rhydon’s base cry, would make more sense for a more menacing monster like Hitmontop (especially considering its freaky original design from the 1997 GS demo), but we can’t deny that Mr. Mime’s moveset anomaly is intriguing.


P4b MissingNo. speculative description: Evolutions and pre-evolutions of P1 and P2d Pokémon, possibly with some general P2 inclusions.

Going off of the pattern for this period, we can safely assume that the numerous MissingNo. within it were also evolved forms of P1 and P2 Pokemon and, of course, the two monsters that appear heavily blurred in the GCCX video (MissingNo. 134 and MissingNo. 135)  fall in this pattern and might be even related to each other.

They could be anything since they might evolve from an unknown MissingNo. Once again, if you know where to find the Game Center CX interview with Satoshi Tajiri in quality better than 480p, please get in touch with us! You could help solve a huge Pokémon mystery.

MissingNo. 137 possesses a cry that is the exact duplicate of Dragonair’s.

This could suggest, as is the case with 094 and 095, a saurian, draconic or even amphibian appearance. As we recently found out, Gyaasu/Gyaoon used to have that very same base cry with default parameters, so we might even speculate that it would have had a pre-evolution in this slot, had it made it into the 190 roster.

MNo. 094 and 095 also share the same base cry as MNo. 137, however usually the evolution has a lower pitch and it’s longer, while 137’s cry is shorter than 095’s and has a higher pitch. It could be that 137 evolved into 95, serving as a mid-stage between 94 and 95, for example, but 137 and 94 have cries that are too similar in pitch (137 is slightly shorter). Differences that minuscule don’t really indicate an intended connection, and it would be an exception to the P4b pattern, as no P3 evolution line seems to have ever been considered for expansion in the later periods.

Frankly every P1 Pokémon might have been considered for evolution during this phase. Our not-yet-evolving P1 candidates are: Lickitung, Scyther, Pinsir, Tangela, Onix, Gyaoon or “O” (if they survived) and the other P1 MissingNo. Lickitung is a strange lizard/amphibian hybrid, so its evolution may have been another contendant for MNo.137, however we’re again facing the same old sprite issue: neither Tangela nor Lickitung’s sprite look downsized (but this doesn’t completely exclude the possibility of their relatives being among the P4b MissingNo). 
Less likely are Kangaskhan and Lapras, and, perhaps, a different Blastoise pre-evolution. Also possible are P2d evolutions, like proto-Animon and a Barunda evolution.



P5 MissingNo. 157-166 speculative description: structured similarly to P3a. Elemental two stage lines inspired by real-life animals, but with kind of a P2b ecosystem awareness and purpose to populate the near-final locations.

We already know that MissingNo. 159 and 160 are proto-Kotora and proto-Raitora, as seen in the “Kaiju Zukan” pages shown in the GCCX interview, so we can assume that MissingNo. 161 and 162 are also a 2-stage evolution line with features common to Pokémon they are surrounded by – mundane, real-life animal inspirations with an obvious elemental or anatomical feature.

P5 MissingNo. 169-175  speculative description: Uncertain. Minerals, Gift Pokémon or P2b pre-evolutions.

What could MissingNo. 172, 174, and 175 be? Pokémon ranging from 169-173 are a seemingly random assembly, dedicated to fine-tuning the game by adding monsters related to gameplay and refining previous evolution lines. However, there are too many missing ones to discern a more specific pattern. One common key could be a shared inorganic quality between Geodude, Porygon, Aerodactyl, and Magnemite, or a “gift Pokémon”  pattern related to the gameplay like Porygon and Aerodactyl.

Geodude and Magnemite could also suggest a pre-evolution trend for P2 Pokémon, especially seeing how rare these were in P4. Another possibility is that they were scrapped pre-evolutions for Jagg or Deer, judging by their more inorganic appearances in comparison to the other 2b MissingNo.

P5 MissingNo. 176-190  speculative description: Wartortle’s original evolution and a three-stage elemental line, possibly Grass. Alternatively two elemental two stagers, one of them Grass-type.

The final part of the list finally introduces the starters, Charmander and Squirtle, a bunch of Missingno, and then the version exclusive grass types. Let’s analyze MissingNo. 181-184. 

As we’ve already seen, slots 182-184 are occupied by the Ghost and fossil skeleton sprites. For speculation’s sake, we’re going to assume that these sprites replaced actual pre-existing Pokémon, as Morimoto’s record may suggest.
The Leaf Stone had been recently added to the ID list; this may have encouraged the crew to design more Grass-type Pokémon. There was already a bunch of Grass-type lines dating from P1a, but they became quite sparse throughout the rest of the periods. Could the abundance of Bellsprout and Oddish throughout the region compensate for some rejected Pokémon? More Grass-types among the MissingNo. might also explain why Gen I had only one pure Grass-type. 
Thus it wouldn’t be too far-fetched to place a third Grass-type line among these MissingNo.

As a side note, could proto-Leafeon have been added as soon as the Leaf Stone was coded into the game?

As incredible as it might sound, placement and cry data suggests that an evolution of Wartortle and a design counterpart to Charizard is one of the most logical identities for MissingNo. 181. The pattern can be found in the cry parameters, each starter line uses the same base cry for every stage, except for Blastoise, who uses a different one from Squirtle and Wartortle, while MNo.181 does.

Each stage of the Charmander and Squirtle line uses the same cry parameters. In fact, Charizard and 181 share the same parameters applied to different base cries, just like Charmeleon and Wartortle.

The story of the starters might’ve gone like this: by P5, “Ivysaur” (proto-Venusaur) was the only future starter with two evolutionary relatives in existence, an evolution line that wasn’t probably conceptualized with the three-starter idea in mind. Someone looks at the Bulbasaur line and thinks it should be the Pokémon you start the game with, along with other similar elemental colleagues. 
The Charmander line is created, duplicate cries slotted in for a water line, and a turtle line is designed, totally independent from Caravaggio.
When the time came to cut the monsters, the crew probably deemed two turtle lines redundant and chose to axe Mno. 181 and keep the older Capumon, Caravaggio. Seeing the P4b trend of completing P1 lines, it wouldn’t be surprising if at that point Caravaggio had already gotten a pre-evolution, which was also scrapped in favor of the Squirtle line.
If that’s the case, then this scrapped alternate Kamex would have been designed by Atsuko Nishida beyond any doubt, as she designed the other stages of Squirtle and the entire Charmander line. This final evolution could have further developed the Minogame traits that were present in Wartortle.





INTRO P1 P2 P3 P4 P5



  1. I think that lack of grass monsters could be explained by some kind of mentality – I mean, look at first Telefang, they are all named after plants, and yet there are NO plants among them, at all (unless you count green scales/feathers on two of them as leaves, or interprent Musa’s shell as plant-based), as if they don’t come into mind when people think “cool, desirable monster”.

  2. I bet more people at Game Freak have access to the Kaiju Zukan than we have been led to believe. The only reason it hasn’t been leaked like the Spaceworld demo is that you can’t scan all the pages before everyone else comes back from lunch.

  3. Really awesome list you have here! I’m trying to do my own digging on some of this stuff myself, but haven’t had any more success than you have. However, as I was looking at your images of 134 and 135, I noticed that they seem to look like spheres linked together with thin structures. In a way, they almost seem to resemble “Cactusmon” (Missingno. 67). 134 even seems to have some “cactus spikes” sticking out of the sides of it, if you squint at the sprite the right way. If 134 and 135 were in fact pre-evolutions of 67, then the progression of the number of spheres would go 2,3, and possibly 4. Of course, it’s definitely too hard to tell at the moment, but I think it’s something worth looking out for in the future.

  4. I wonder if the reason why MissingNo.s 182-184 are sprites for fossils and Ghost is that originally, the fossils and the Ghost were coded as Pokémon which you could battle. I admittedly don’t know the games very well, but I know that Ghost-type Pokemon are “Ghosts” before their identities are revealed. It thus may have been that Ghosts were programmed as their own Pokémon rather than as a cosmetic disguise. As for the fossils, perhaps you would have to have stored the fossils as Pokémon and then resurrected them later.

    It is possible that this may have overwritten data for older Pokémon, given that 190 Pokémon has been confirmed as the number which were created, but this theory does explain why these sprites are linked to, especially as they all share the common theme of being things which turn into Pokémon after they are obtained.

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