The film has generated a media franchise including three film sequels, a stage musical production, a video game and a children's TV cartoon. In 2019, it was announced that Legendary Entertainment would be producing a reboot of the film, with original creators Lloyd Kaufman and Michael Herz of Troma Entertainment serving as producers and Macon Blair serving as writer and director.

Mitch Cohen as The Toxic Avenger

Melvin Ferd Junko III is a weakling who works as a janitor at a health club in the fictional town of Tromaville, New Jersey, where the customers—particularly Bozo, Slug, Wanda and Julie—harass him constantly. His tormentors murder a young boy on a bike with their car and take photos of the carnage afterward. They trick Melvin into wearing a pink tutu and amorously hugging a sheep. He is chased around the health club and out a second story window. He falls into a drum of toxic waste, which sets him on fire. After running down the street, Melvin douses the flames in his bathtub. The chemicals transform him into a hideously deformed mutant with superhuman size and strength.

In 1975, Lloyd Kaufman had the idea to shoot a horror film involving a health club while serving as the pre-production supervisor on the set of Rocky. At the Cannes Film Festival, Kaufman had read an article that said horror films were no longer popular, so Kaufman claims that he decided to produce his own version of the horror film. The film's final outcome was less a bona fide horror film and more of a campy superhero-spoof with extreme violence embedded throughout. The setting of the movie in a health club and the movie was given a working title of Health Club Horror.

On December 10, 2018, it was announced that Legendary Pictures had the rights to reboot the film, with Kaufman and Herz set to serve as the film's producers. In March 2019, Macon Blair was announced to write and direct the upcoming reboot.

During an interview with in January 11, 2021, Kaufman praised Blair and his script saying:

"Macon Blair knows Troma better than I do. He’s seen everything. He’s seen the cartoon [Toxic Crusaders], he’s seen the Halloween special, he’s seen everything. And he loves our movies... I’ve read the script and it’s better than the original and I leave it to him. If I’m called upon, I’d be happy to jump in. I learned on the musical to leave the creative to the creative. I learned to let them ask so if they want me, I’m there... I hope that Legendary keeps going. If they let Macon Blair direct it, I think it will be terrific. He knows the Troma sense of humor, the combination of slapstick and satire with the environmental theme."

In December 2020, Peter Dinklage is set to star. In April 2021, Jacob Tremblay also joined the cast with Taylour Paige, who joined in May 2021. On June 12, 2021 it was announced that Kevin Bacon had joined the film as the villain followed by Julia Davis and Elijah Wood on June 16, 2021 with Jonny Coyne and Sarah Niles on June 17. In 2022, the completed work was officially rated R for "strong violence and gore, language throughout, sexual references and brief graphic nudity," thus contradicting earlier claims of a PG-13 rating.