Zweilous

“After it has eaten up all the food in its territory, it moves to another area. Its two heads do not get along.”

— Pokémon Alpha Sapphire

“Since their two heads do not get along and compete with each other for food, they always eat too much.”

— Pokémon White

“The two heads do not get along. Whichever head eats more than the other gets to be the leader.”

— Pokémon Black 2