[spondylosaurus]

The original Pokemon games (Red, Blue, Yellow, and Green in JPN) were also full of notorious programming idiosyncrasies and glitches. I'm not sure how safely you could insert new data into the game without poking the bear too much.

https://bulbapedia.bulbagarden.net/wiki/List_of_glitches_(Ge...

https://bulbapedia.bulbagarden.net/wiki/List_of_battle_glitc...

https://bulbapedia.bulbagarden.net/wiki/List_of_overworld_gl...

The 1/256 glitch is a fan favorite because to this day it still fucks over people who play Gen 1 competitive PvP battles.