The main protagonist of the series. He started out as a nerdy mop boy named Melvin Junko, but became a hideously deformed creature of superhuman size and strength after a prank played on him resulted in him falling into a barrel of a toxic waste product called Grossolium-90. Since then, he has dedicated himself to ridding Tromaville of crime and pollution.
- Adaptation Name Change: Downplayed. Rather than the Toxic Avenger, Toxie's full designation is the Toxic Crusader.
- Adaptational Heroism: This incarnation of Toxie is content with simply beating up his enemies than killing or mutilating them.
- Bald of Awesome: He loses his hair after his mutation and is a very formidable butt-kicker.
- Catchphrase: Goes through a few of them, but ultimately settles on "It's clean-up time!" in episode 4.
- Improbable Weapon User: His weapon of choice is a mop, which became sentient by the same toxic waste that mutated him.
- Nice Guy: Like in the movies, Toxie is a very kindhearted fellow and really likes to help people out and protect them from criminals.
- Non-Human Sidekick: He has a pet pink blob named Blobby.
- Spider-Sense: Has one in the form of his "troma-tons", which cause odd sensations when he's around evil.
- Super Strength: Aside from his above-mentioned Spider-Sense, Toxie's main asset is his superhuman size and strength.
A pilot who mutated after flying through a hole in the ozone layer and crashing into a silo of radioactive pepper.
- Gag Nose: He has a giant nose because of his mutation.
- Handicapped Badass: He has a wheel for a foot and is still a mighty member of the team.
- Sneeze of Doom: It's his power to be capable of powerful sneezes.
A soldier who gained power over plants and vegetation after falling into a radioactive swamp.
- Brought Down to Normal: Believes himself to have lost his powers in "Tree Trouble", even though he had them all along and the real problem was that he was attempting to use them on Killemoff's mutated trees. He's still capable of saving the day alongside the Crusaders, though.
- Green Thumb: He can control any kind of plant. Even industrial plants.
- Heroes Want Redheads: He falls for a red-haired tree surgeon in "Tree Trouble".
- Retired Badass: A former soldier who retired to pursue crime-fighting after falling into a radioactive swamp.
A mad scientist and a slacker telegram delivery boy who fused into a two-headed being after an accident with an atom smasher. They started out working for Dr. Killemoff, but subsequently sided with the Toxic Crusaders.
- HeelFace Turn: They started out as working for Dr. Killemoff before joining the Toxic Crusaders.
- Mad Scientist: Dr. Bender worked with Dr. Killemoff to coat french fries at Burpo Burger with a serum called Magoop 82, which made whoever ate the fries become forgetful, near-sighted, and elderly. He still has shades of being an eccentric genius after becoming a Toxic Crusader.
- Multiple Head Case: Bender and Fender share a body and are often at each others' throats.
- Surfer Dude: Fender talks like a Californian surfer and even wears sunglasses and swimming trunks.
A dog and a homeless man who were merged into a humanoid dog by toxic waste.
- Barefoot Cartoon Animal: He doesn't wear shoes.
- Heroic Dog: In his case, it's heroic doglike mutant.
- My Instincts Are Showing: Even after becoming capable of human speech and walking on two legs, Junkyard still acts like a dog at times, at one point even barking when told to speak.
- Nice Hat: He wears a red cap.
- Toxic Waste Can Do Anything: How he became a mutant.
- Uplifted Animal: Junkyard acts like this as the dog's mind is the only one present after his mutation.
- I Want Grandkids: She mentions that she wants grandchildren in "Toxie Ties the Knot".
Toxie's near-sighted girlfriend.
- Bait-and-Switch: In the first episode, when she gets a good look at Toxie with her glasses on, she starts screaming... not because he's a hideously deformed creature of superhuman size and strength, but because his necktie clashes with his outfit.
- Brainless Beauty: She's a knockout, but isn't very bright. Toxie even lampshades this in the first episode by saying "Okay, so she's just beautiful" after describing her as intelligent and beautiful when she turns out to be screaming because she thought his necktie was hideous.
- Dreadful Musician: Her accordion-playing is loathed by everyone except Toxie.
- Expy: She is similar to Sarah/Claire from the movies due to being Toxie's blonde girlfriend, except she's near-sighted instead of blind.
- Hollywood Tone-Deaf: In addition to being terrible at the accordion, she's also a dreadful singer.
The main villain of the series and head of Apocalypse, Inc. He is actually a member of a race of insectoid aliens called Smogulans, who plan to pollute Tromaville in order to make it easier for them to thrive.
- Big Bad: He is the main antagonist, although he himself is The Dragon to Czar Zosta.
- Corrupt Corporate Executive: Other than running a company that does nothing but pollute, his real agenda is to prepare the Earth for Smogulan invasion.
- Multi-Armed and Dangerous: Like all Smogulans, he has four arms.
- Nonstandard Character Design: Compared to other Smogulans, he has no pupils. He's also the only one who needs some form of life support to exist on Earth.
- The Starscream: In at least one episode, he attempts to overthrow the Czar.
- They Call Me Mister Tibbs: A running gag is for him to correct anyone who addresses him as just Killemoff with "It's Dr. Killemoff!"
One of Dr. Killemoff's minions. An obese cyborg who always accurately predicts how the Toxic Crusaders will save the day, only to be ignored.
- Cassandra Truth: His theories on how the Toxic Crusaders will foil their plans always turn out to be accurate, but Dr. Killemoff always dismisses his predictions as absurd.
- Co-Dragons: He and Bonehead share the position of Dr. Killemoff's main lackey.
- Cyborg: At least half of Psycho's body is fitted with mechanical parts.
- Deadpan Snarker: Often makes snide remarks about Dr. Killemoff's refusal to listen to his predictions and Bonehead's stupidity.
- Disguised in Drag: When disguised, he's frequently shown in female disguises.
- Fat Bastard: His body mass is rivaled only by his snarkiness.
- I Warned You: Often boastfully says "I told you so" when his predictions turn out to be right, which is all the time.
- Only Sane Man: He is frequently the only one of the bad guys with a lick of common sense.
A punk who pranked Melvin Junko by having his girlfriend trick him into wearing a pink tutu, indirectly causing his transformation into the Toxic Crusader. He was later thrown into a barrel of acid rain by Toxie and gained a skeletal appearance, subsequently becoming one of Dr. Killemoff's minions.
- Co-Dragons: He and Psycho are both Dr. Killemoff's main henchmen.
- Dumb Muscle: Relatively speaking. He's dim as heck and he tends to be relied on in doing the heavy lifting.
- Expy: He fills in for Bozo and Slug from the original movie as the bully who picks on Melvin and is indirectly responsible for his mutation. He even looks a bit like Slug before his mutation.
- Laser-Guided Karma: After indirectly causing Melvin Junko to become Toxie, Toxie returns the favor by causing him to turn into a skeletal mutant.
- Meaningful Name: The name "Bonehead" is doubly fitting because he has a skeletal appearance and he's an idiot.
- Nice Job Fixing It, Villain!: Granted, this was before he joined Killemoff, but Bonehead was responsible for making Toxie into who he was, making Killemoff's job much harder.
Dr. Killemoff's boss and the Czar of Smogula, who sometimes drops in on Killemoff attempting to put him on the right track towards polluting Tromaville.
- Affably Evil: Despite constantly berating Killemoff for his myriad failures, he's still pleasant to just about everyone else and even postpones an attack because Toxie freed him from an assassination attempt.
- Even Evil Has Loved Ones: Genuinely does care about his wife and daughter, and even respects Toxie when he's his soon-to-be son-in-law.
- Evil Is Petty: The reason Czar Zosta wants to claim Earth in the name of Smogula? He doesn't want to pay last month's rent.
- Greater-Scope Villain: Killemoff works for him.
Mayor Max Grody
The corrupt mayor of Tromaville who frequently conspires with Dr. Killemoff.
- Child Hater: He admits to not liking children in the second episode.
- Cruella to Animals: He mentions in "A Sight for Sore Eyes" that he wears shoes made of endangered species.
- Expy: Since he's an obese and corrupt mayor, he's basically the cartoon's equivalent of Peter Belgoody from the original movie.
- Fat Bastard: He's overweight and a very unpleasant person.
- Kick the Dog: He gloats about kicking his own mother out of her home in "Club Fred".