Robomonkey is a one-time villain that only appeared in Robomonkey Shines.
It was built by Tommy from the remains of Donnie's old computer as a present for Robotboy. However, when Tommy went to school, because of Robotboy reminding him of Donnie, Robomonkey went berserk and became an annoying house-wrecker, making a huge mess in Tommy's house.
When Tommy returned from school, Robotboy kicked Robomonkey away, only for Robomonkey to be found by Dr. Kamikazi and Constantine. Kamikazi wanted to make him the mascot for Kaziland, but Robomonkey took control over his car and went on with his rampage. What happened with him afterwards is unknown.
Gallery
Robomonkey while being built
Inside Robomonkey's head