Tromaville has a monstrous new hero. The Toxic Avenger is born when meek mop boy Melvin falls into a vat of toxic waste. Now evildoers will have a lot to lose.

In Tromaville, Melvin works in a health club with his bucket and mop as a janitor. The sadistic and bullies Bozo and Slug and their girlfriends Julie and Wanda, who love to hit-and-run people in empty streets, play a cruel prank in Melvin and he falls off the window in a barrel of toxic wastes in a truck parked in front of the health club. He turns into the strong monster Toxic Avenger and protects the town from criminals. He saves the blind Sara from a rape and soon they become sweethearts. At the same time that he is worshiped by the residents, the corrupt Mayor Peter Belgoody and his gang want to destroy him.—Claudio Carvalho, Rio de Janeiro, Brazil

This is the story of Melvin, the Tromaville Health Club mop boy, who inadvertently and naively trusts the hedonistic, contemptuous and vain health club members, to the point of accidentally ending up in a vat of toxic waste. The devastating results then have a transmogrification effect, his alter ego is released, and the Toxic Avenger is born, to deadly and comical results. The local mop boy is now the local Superhero, the saviour of corruption, thuggish bullies and indifference. Troma classic with good make-up effects and stunts, a pleasant surprise indeed.—Cinema_Fan

Melvin is a social misfit who works in the Tromaville Health Club. He is always suffering the abuse of two bullies and their respective girlfriends and the four are also murderers. But all the abuse is going to end when Melvin accidentally falls into some barrels with toxic material. Now he is "The Toxic Avenger" and soon he will be the hero of Tromaville and a menace to the corrupt mayor.—eric from Mexico City