Rabbid

Rabbids are a species of hyperactive anthropomorphic rabbits originating from Ubisoft's  franchise. Their name is a pun of "rabid", a term used to describe an animal with rabies, or a person who acts insane. Following their popularity, the Rabbids would evolve from recurring enemies to temporary quasi-protagonists that spawned their own spinoff series titled .

Their first crossover appearance with the Mario franchise is with Mario + Rabbids Kingdom Battle, where five different Rabbids are playable, and several others appear as enemies or other non-playable characters.

In Super Smash Bros. Ultimate, Rabbid Mario, Rabbid Peach, and Mega Rabbid Kong (all three being characters introduced in Mario + Rabbids Kingdom Battle) appear as spirits. The January 28th, 2020 update to Super Smash Bros. Ultimate that added Byleth as a playable DLC character, also added DLC Rabbid headgear that the Mii Fighter can don.