Sir Rebral has green goggles like Dr. Hare, a scar on the right side of his face, and a beard that wraps around his mouth. He was in jail for playing mind, or "cerebral", games.
Role on Super Power Island
After the radioactive meteorite crashed into the Prison, he, along with the rest of the inmates, was mutated with powers and given mind-control and telekinesis. He escaped to City Park and somehow knocked the head off of the statue of Curtis. Sometime later, he climbed onto the statue to ensue the fight. Soon you arrive, and he uses telekinesis to form a shield of rubble around him. He also uses his powers to throw rocks at you. You must lead the boulders into him to make him angry. Then he'll make the ground start to shake. Rocks will rise from the ground and hit you, sending you flying. You have to go to the left of the bathroom, push the boulder next to the statue, and then, when the ground is about to erupt, move the mouse towards Sir Rebral. The ground will push you up, but the boulder will hit Sir Rebral, knocking him unconscious. Then the hero uses the Anti-Power Handcuffs to weaken Sir Rebral to the point where he can't use his powers. The hero escorts Sir Rebral back to Super Power County Prison and promptly locked up for good.
Role in Astro-Knights Island
While in the act of stealing the Queen's crown jewels, Sir Rebral was caught and whisked away to Super Power County Prison. He is shown on his Criminal File to be arrested also for playing mind games. However, he is not seen or mentioned in the island itself.
Role on Super Villain Island
He is one of the villains that must be defeated to retrieve Ned Noodlehead's comic books. You must catch 20 of the tomatoes he throws at you.
- His name is a pun on the word "cerebral."
- He appears using Telekinesis in the profile quiz question "If you had a super power, what would it be?"
- His skin color in Super Power Island is different from his skin color in Super Villain Island.
- In Dr. Hare's Secret Lab there is a soldier that has his beard.
- According to Sir Rebral's profile in the 2011 Poptropica Villain Showdown, he believes he is descended from royalty. This may explain why he attempted to steal the Queen's crown jewels as he may believe that they were rightly enthroned to him.
- In Poptropica Adventures, he wears blue clothes and an orange cape.
- in Poptropica Adventures when you first see him he does not have his goggles on.