Monsters from Final Fantasy IX. They pretend to be friendly monsters, but run away upon being the Diamond they demand and give nothing in return.
Gimme cats also appear in Final Fantasy XIV as one of Sugar Riot's summons in the Savage version of her raid encounter. Like the Yan (Final Fantasy), it gained notoriety within the fandom, due to its ingame dialogue and being able to wipe the party if left alive for a prolonged period of time.