Donkey Kong was an antagonist in the Mario arcade games. He later appears as the anti-heroic character Cranky Kong in the Donkey Kong franchise.
Donkey Kong 3
The original Donkey Kong attacks the greenhouse of the game's protagonist Stanley the Bugman. He has to be defeated in all three stages.
Donkey Kong Land
In Donkey Kong Land, Cranky Kong becomes an antagonist once again when he becomes jealous of Donkey Kong and Diddy Kong success over King K. Rool. He then challenges in a bet with the two to see if they could prove themselves as heroes, by defeating King K. Rool once again. After defeating King K. Rool, Donkey Kong and Diddy Kong would finally prove themselves as heroes once again.