I have a level 100 gengar in Pokemon yellow. However, when it faints opponents, it still gains exp. Is this a glitch or a bug or something? I was just wondering since I found it strange.
After a certain amount of experience points have been gained, a Pokémon will grow a level, all the way up to level 100, where a Pokémon will no longer gain experience (in Generations I and II, the game will still erroneously state that it has gained experience points).
source So it's a bug.
