He is Dumb Man's arch-nemesis and a well known crime boss in the city of Underwood, he first encountered Dumb Man after he followed his right hand man to their hideout, from that point on they've had a rivalry that has never been topped by any of Dumb Man's other villains

Real Name: Dean Matthews

First Appearance: Dumb Man: Richard Rises

He is under the belief that he is Dumb Man's arch-nemesis, he used to be friends with Dumb Man back when they were roommates (although Dumb Man doesn't remember this as he is pretty Dumb, man), every time he tries to do bad he ends up helping Dumb Man, he may of only had a cameo appearance so far but he will return one day

Real Name: Howard Shufflebottom

First Appearance: Dumb Man: The Other Goggle-Stone

This guy is obsessed with being evil, he used to work on a ferry and with his evilness he decided to charge everyone by a single penny, after years of doing this he was able to buy his own Ferry and charge high prices for it, after getting even more money he was able to buy a mansion, he is also really proud of his gassy serial killer, Killer Gassy

Real Name: Gilbert Grimes

First Appearance: Dumb Man: Wrath of the Ferryman

Helmet Man is the first supervillain that Dumb Man ever fought, he first became a supervillain to get revenge of famous Billionare Radnor Crete

Real Name: Nardoo Patterson

First Appearance: The Mediocre Dumb Man

Ghost Mask is the right-hand man of The Mannequin Man, he is extremely loyal to his boss and has been with him through thick and thin, as well as through Dumb Man and Goggle-Stone

Real Name: Mason Webb

First Appearance: Dumb Man: The Mischevious 3

The Green-X is a genius inventor who needed money so had to work for the mannequin man since he had no other option

Real Name: Gene Pryor

First Appearance: The Mediocre Dumb Man (upcoming episode)

One of The Mannequin Man's goons, who inspires to do great things in the future...

Real Name: Damien Fox

First Appearance: The Mediocre Dumb Man (upcoming episode)

I wonder if he will have anything to do in the future?

First Appearance: The Mediocre Dumb Man

Mr. Unstoppable has lived for eons yet still is young as he is Unstoppable, nothing can stop him, not even the sun, but he does have one massive weakness, if he forgets he is unstoppable, he becomes stoppable until he remembers again

Real Name: John P. Unstoppable

First Appearance: Dumb Man Vs. Mr. Unstoppable

One day The Mannequin Man hired this guy to kill Dumb Man, but however things didn't go according to plan when he mistook a Mr. Smaz statue for Dumb Man, while he died after that encounter, he came back to life, and his true potential will be reached one day,  he is the potential man of the Dumb Man franchise

Real Name: Richard M. Man

First Appearance: Dumb Man: Richard Rises