Donny is a green grass ogre and the titular main villain of the episode "Donny" of Adventure Time.
He was voiced by Kevin Michael Richardson.
He acts mean to a village of house people who share living space with him. Finn and Jake bring Donny to their house and turn him into a nice person. However, the Why-Wolves tell Finn that Donny's attitude keeps them from attacking the house people, because his jerkiness produces a gas called obnoxygen which is extremely deadly and dangerous to Why-Wolves and without him they will wipe out the inhabitants.
Finn and Jake return with Donny, who is now nice and interested with singing. They make fun of his singing until the humiliation reverts him back into a jerk. The wolves flee and Donny goes back to bullying the building people, proud of it. He then sadly watches Finn and Jake leave promising to never forget them for helping him being a jerk again.
He was seen in "All of the Little People" as one of the many living toy versions of the people in Ooo.
He was seen again in a picture in the credits of "Water Park Prank" as one of the many characters who are banned from the water park along with the Earl of Lemongrab, Lumpy Space Princess, Tiffany Oiler, Ricardio, Magic Man, Squirrel and Ice King.
- After Jake teaches him not to be a jerk, his eyes are less bulged and closer together.
- Donny can play the Cello.
- He is mentioned in "Music Hole".
- Jake called Donny, Donald at one point.