Bunny

Bunnies are effectively the most popular animals in the Death will Come mod. They spawn in the plains and they hop around, as well as eating carrots. They have a one percent chance to drop a Guitar.

Grim Reaper's Encyclopedia Entry
Have you seen a purple, humanoid one carrying a guitar? That's the rarest kind.

Trivia
Their GRE entry and their rare drop are both references to the game Five Nights at Freddy's.