Hoodoo Guru the Voodoo Villain or Hoodoo Guru for short is a character who appears in the episode "Swamp Mates."
He is a buff green man with a voodoo mask for a head. He also wears orange gloves, a kelp skirt, green boots and a brown belt with a skull in the middle. When he is seen as a shadowy figure, he wears some dark blue clothing; his cloak and fedora with a red line, and also wears red gloves and scarf. He has the power of voodoo and can use voodoo dolls to control people and make them do his bidding. He is a big fan of Mermaid Man and Barnacle Boy, as shown by his collection of superhero figurines from the show.