'M

Index zero. The slot before Bulbasaur, before everything, the very first entry the species table has, and it was left empty. Surface that emptiness in a battle and you get 'M: a pile of grey static with a name that is barely a name. It looks like MissingNo., and for years people assumed they were the same thing. They are not. 'M has its own data, its own broken behavior, and one genuinely miraculous trick that MissingNo. cannot do.

Everything here is decoded from a real Pokemon Red ROM by reproducing the game's own out-of-bounds reads. Where the five cartridges disagree, I decoded all five.

It becomes a Kangaskhan

This is the fact that makes 'M legend. Level it up, and this scramble of noise evolves into a perfectly ordinary Kangaskhan: a real, finished, mother-with-a-baby Pokemon that Game Freak drew by hand. No event, no trade, no trick beyond the levelling itself. Static becomes a mom. Watch it happen, rebuilt from the ROM in the game's own evolution animation.

'M → level up → Kangaskhan

Why does it happen? 'M's evolution data is read from a pointer that never pointed at evolution data. The game follows it anyway, and the garbage it finds there just happens to spell out a valid instruction: at level 80, evolve into species number two. Species two is Kangaskhan.

And Kangaskhan is not the only door. The same garbage stream also contains half-formed paths toward Dragonite, Venusaur, Abra, Dugtrio, and, fittingly, MissingNo. itself, all at impossible levels. But Kangaskhan is the one that reliably works, and the one that turned 'M from a curiosity into a playground myth.

What it is made of

Under the static, 'M is a defensive lump that cannot fight. Its defense is a solid 153, but its attack and its speed are both exactly zero. It is nearly impossible to hurt and nearly incapable of hurting you, a wall that just sits there. Its one aggressive instinct is the move it opens with: Explosion, a suicide attack that, powered by an attack stat of zero, does almost nothing except make the point.

GLITCH TYPENORMAL Catch rate 153.

Moves it knows

From the start: an unprintable glitch move, Defense Curl, and Explosion. Deeper in its garbage learnset it finds Metronome, twice, along with Petal Dance and a scatter of moves the game cannot name. Metronome is the interesting one, because it picks a random move from the entire game, so a creature that cannot attack can suddenly do anything at all, once, by accident.

Across five cartridges

The empty slot is not empty in the same way everywhere. I read index zero out of all five Gen 1 cartridges I have. Red and Blue are identical. Yellow moved the data. And the two original Japanese carts, Green and Red, match each other but differ from every western version, because their ROM is laid out differently underneath.

Look at the raw bytes: Red and Blue are the same string. Yellow is a completely different one. The Japanese pair share a third. Same slot, four different creatures, decided entirely by which cartridge you are holding.

Where it comes from: index zero and the Mew glitch

'M is not something you find in tall grass by luck. Like MissingNo., it is summoned by a memory trick, and because it sits at index zero it is central to the most powerful exploit in the game. Certain names, run through the old man glitch on the Cinnabar coast, land on slot zero and produce 'M. The same slot-zero behavior is a building block of the Mew glitch, the sequence that lets a player conjure the one Pokemon Nintendo never released. 'M is the doorway creature: harmless on its own, load-bearing for everything strange you can make the game do.

Hear it

A cry is three bytes the game looks up by index number: a base sound, a pitch, and a length. 'M's index lands on a base value of 0x38, which points past the real cries into sound data that was never a cry at all, so what comes out is genuinely broken. I read those three bytes from the ROM and rebuild the sound live from the Game Boy's two pulse channels and its noise channel. This is not a recording.

Does it still work in 2026?

Yes, in the place it matters most. 'M lives at index zero, and you reach it the same family of ways you reach MissingNo., through the old man trick and the slot-zero encounters on the Cinnabar coast. Nintendo re-released Red and Blue on the Nintendo 3DS Virtual Console in 2016 and left the glitch untouched, so the empty slot, the Kangaskhan evolution, and the rest of it all still run on hardware you can buy today.

The Kangaskhan evolution survives too: it is baked into the same out-of-bounds data, so on any of the versions above, levelling 'M still turns static into a mom.

Fight it yourself

My from-scratch recreation of the Red battle engine, running natively on the page. The enemy is locked to 'M, its zero attack and zero speed and immovable defense intact. Build your own team and try to break the wall, if Metronome does not break you first.

Every number, sprite, and animation on this page was decoded from a Pokemon Red ROM by reproducing the game's own out-of-bounds reads. Part of The Glitchhouse. Next door: MissingNo.