The Debull is a bull-like creature found only in Yoshi's Island DS. He appears to be a brown bull with horns and a tail with a red spot at the back, sort of resembling Poochy's tail.
Yoshi's Island DS
Debulls are listed as land enemies in the Enemy Museum. When Yoshi is near it, it gets angry and follows him, allowing him to easily lure into chasms and such. The only way to defeat it is to use Baby Bowser's fire. To stun it, Yoshi must egg it or let it crash into a wall or post. With Baby Donkey Kong, it gets stunned longer when egged by him.