Toxic Crusaders cleaned up Toxie's act considerably. Toxie was still a grotesque mutant endowed with superhuman powers, but underneath it all, he was a good-hearted, law-abiding citizen. Another change from the films was that the toxic waste also mutated his mop into a sentient being that would sometimes battle enemies by itself or motion to Toxie ideas on how to solve problems. The villains were still polluters, albeit polluters from a different world. Hailing from the planet Smogula, Czar Zosta, Dr. Killemoff, and Psycho wreaked ecological havoc with the help of Tromaville's corrupt Mayor Grody. Bonehead, a street punk who bullied Melvin, joins them in the first episode.
Dr. Killemoff and Czar Zosta were cockroach-like extraterrestrials from the planet Smogula, which is a world where pollution is natural as fresh air and water is natural to Earth. Natives of Smogula thrive on pollution and need it to survive. For unexplained reasons, Czar Zosta and other Smogulans were able to withstand Earth's atmosphere without problems while Dr. Killemoff wears an breathing apparatus to survive. Killemoff, like most bad guys, also had a seemingly endless army of identical poor marksmen called Radiation Rangers.