Chuckles wanted to be leader of the group and when the gang joined Slade, he eventually back-stabbed Luciaus and joined Joker with Hinkle and the Noid to get even with the other members who joined force with the good guys. He was defeated, though.
Angry, Chuckles needed to think of a plan for revenge. The plan eventually came when Marceline's dad arrived and murdered his nemesis. Amazed, Chuckles offered his partnership with the other 2 traitors to him. Marceline's dad accepted and they helped him in his plan by devising schemes to get Luciaus. Eventually, like his team, he was killed by a turn coat, Darkwarrior.