Murder Mime was a Mr. Mime who gained infamy after surviving many attempts to deposit it at the expense of several other Pokémon being released.
Murder Mime was viewed as being a near useless Pokémon due to having weak attacks and was seen as being nothing more than a waste of space on the team. Attempts to deposit it ended badly however.
Murder Mime is depicted as being determined to remain at Abe's side no matter what, even arranging for the release of several other Pokémon to ensure its safekeeping. It is possible that it wanted to control Abe for some reason.