|Please note that this glitch only exists in the Japanese versions of the game, or is otherwise a glitch from a Pokémon game which was only released in Japan.
Map corruption caused by this glitch
The type 0x20 corruption glitch occurs in Pokémon Red and Green and is caused by three glitch Pokémon; ヲイﾞマﾞヅパ (0xE2),
をイﾞビぱパ (0xE5), and ゃアジさイﾞ(0xE8).
This glitch is caused by those glitch Pokémon's first type which has an index number of 0x20. This type is type 1 for all glitch Pokémon in family 245.
If you view the type 1 of one of the applicable glitch Pokémonn, the game may corrupt the map when its type is '9999999.....'. If you view the stats of a normal Pokémon before viewing this glitch Pokémon its type may be different and won't corrupt the map, however, it may be '9999999....' again after saving and restarting.
With type 20h's map corruption, you may be able to walk through walls, but it often traps you. You can work around this by encountering a wild Pokémon by walking around or with 5かい.
These glitch Pokémon are available with the fossil conversion glitch (Japanese) or arbitrary code execution.
Arbitrary code execution
The following code for arbitrary code execution (e.g. with ５かい or てへ (0x7B) redirected to item slot 3 will work for obtaining ゃアジさイﾞ(0xE8) as an unstable hybrid Pokémon of party Pokémon 1.
3E E8 EA 24 D1 C9
ld a, E8
ld (D124), a
X Accuracy x232
If you want to change the recipient byte so the DayCare Center gives you back an 0xE8 (you won't see a glitched type immediately though), just change TM34's quantity to 43 (hex: 2B).
- Kazblox (discovery)
- ChickasaurusGL (research, description, YouTube video)