After falliing into a barrel of toxic waste left behind by evil alien mastermind Dr. Killemoff, nerdish Melvin mutates into superhuman Toxie.

Toxie and his mutant friends have to stop people from eating junk food made with a chemical that turns them old and senile.

Dr. Killemoff lures Toxie and his friends to a fake island resort; a humanoid mutant dog wants to join the Toxic Crusaders.

Dr. Killemoff takes over the Crusaders' factory so he can make smog in a can.

Dr. Killemoff plans to use the people of Tromaville to help him create more smog.

The Smogulan scientists find a large pool of high smogtane crude that is perfect for their evil plans, but it's underneath the Crusaders' home base.