The Black Rabbit: an entity that seems pretty familiar to mickey but it became in a monstrosity made of pure evil, when is encountered it makes the sanity meter drop by 10 every time so watch out. - The manual to the game "Really Happy Mouse".
The Black Rabbit is black, tall entity with red eyes and teeth that has a connection to Really Happy Mouse.
The Black Rabbit is a fan-made antagonist in Abandoned Discovery Island.
The Black Rabbit will start rarely start where Really Happy Mouse starts. He starts in Character Prep 3, moves to Character Prep 1, the Staff Area, the Meat Freezer, Lounge, and then the Office. When Really Happy Mouse enters the Office, The screen will flash black, and The Black Rabbit will be seen, holding Really Happy Mouses' head. While standing in the Office, The Black Rabbit's head will shake quickly. Before The Black Rabbit attacks you, you must shut off the power to get rid of him.
- Suffer, Mickey.
- Come here.
- I will find you, Mickey.
- It is unknown why The Black Rabbit has a connection to Really Happy Mouse.
- The Black Rabbit isn't an Oswald variant.
- No 3D model was made, because his body figure is too complicated.