Back when Mojo Jojo tried to take over the world with primates, there was one monkey who didn't get his due - Mopey Popo. Now Mopey is back to try and be evil just as Mojo intended.

The Professor tells the girls all about his younger brother Eugene and how he was such a wild man back in the day.

Mojo is sentenced to do community service for Townsville and begins teaching English at the Learning Annex.

"Custody Battle" Mojo discovers that the Rowdyruff Boys are back and is determined to show them that he is a more evil dad than Him.

The Powerpuff Girls must literally work as one to try and stop Mojo Jojo from destroying Townsville.