Sal Left Thumb is an antagonist in The Amazing World of Gumball.
The Amazing World of Gumball
Sal Left Thumb is a criminal who is wanted in Elmore. He is shaped like a giant fingerprint and wears a black mask. His first appearence was in "The Spoon", when he tries to rob a gas station by scaring the cashier with a spoon. He then tricks Gumball and Darwin into helping him by saying he is donating money to the bald people charity. He seems to be the thumbprint person in the preview "Mom's Warning.".
He can also be seen on the Amazing World of Gumball commercial when they all shout " The Amazing World of Gumball!"
Gumball's mother beats him up after he's placed in a holding cell she was wrongly put in.
He seems to be really dangerous because there is a wanted poster of him in the gas station and on the gate in a neighbors house in The DVD (when Nicole chased the boys) that shows a reward of $25.00 for anyone who captures him. His main weapon is a rusty spoon, which is considered a lethal weapon in the series, hence why he's so dangerous. He also appeared as a cameo in "The Kiss", when Darwin showed Gumball his "Happy Place", and waved at Left Thumb, and waved back at him and then broke a car window, hinting he is not planning on messing with them since he is terrified of Nicole.