Rabbid

Rabbids are a species of hyperactive anthropomorphic rabbit-like creatures originating from Ubisoft's  franchise, where they initially appeared as comedically violent and insane antagonists. Their name is a pun on "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. Aside from their generally chaotic behavior, the Rabbids are known for their loud vocalizations, typically written as "Bwaah!" or some variation, during which their eyes usually become red and unfocused.

The Rabbids' 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 28, 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.

Hybrids of Rabbids and Lumas called Sparks appear in Mario + Rabbids Sparks of Hope, along with some more heroic Rabbids such as Rabbid Rosalina and Edge.