>>18998612Fun fact: that sprite specifically like that because it's loading the graphics from address 0x1900 in RAM, which actually points to ROM bank 0. While different MissingNo. would theoretically load different banks into RAM, it ends up being irrelevant so every front sprite of any MissingNo. is always the same.
The backwards-L shape comes from the fact that byte 0x39FCC (sprite dimensions) is set to 0x88, which means it's set to load an 8×8 tileset for the front sprite despite the maximum allowed being 7×7. And why is the byte set to 0x88? And why does this cause the iconic shape? Because a certain Biker uses a Muk as his second Pokémon, and Muk has an index number of 0x88.