The Mawgu

The Mawgu is the main villain and final boss in Nicktoons: Battle for Volcano Island.

Nicktoons: Battle for Volcano Island
He escapes from his prison. He tries to get revenge on those who sealed him away, through the use of terrible ooze that can corrupt anything making them his minions. To prevent this The Wise Old Crab summoned "The Chosen Ones," to stop him. They overcame many obstacles until reaching him. Timmy, Cosmo, Wanda, Sam, Patrick, and Sandy distract him while SpongeBob and Danny fight him (with some of Squidward's help) and while Tucker and Jimmy finish the Rip-Zipper. After the Rip-Zipper is finished he is sealed within the rip, but vows revenge.

Nicktoons: Attack of the Toybots
The Mawgu makes a cameo as a contestant on "The Biggest Genius" alongside Plankton.