The Chameleon
 (voiced by Daran Norris) is an evil chameleon in a molecular transformation suit which allows him to shapeshift into virtually any disguise or inanimate object. He serves as the one the three main antagonists of the series where some episodes have him collaborating with Verminious Snaptrap and Bird Brain. In "Doom-mates", his name is pronounced "The Cham-a-leon" as a running gag he wanted to get revenge on Kitty Katswell by blowing her up nine times but Dudley heroically thwarted his evil plan, thus saving her. He talks like Peter Lorre and eats any bug he sees, a trait used against him several times. His relationship with D.O.O.M. seems rather strained, since he tends to work separately from the others and once planned to trick them and T.U.F.F. to destroy each other. He said he wanted to go to D.O.O.M.'s weekly ice cream socials, but he was never invited. As a running gag, he often tries to wear some type of eyewear only to have his eyes go around or through them. He can sometimes be very random when disguised (For example, in "Internal Affairs" he tells the soldiers "semper fi" and "remember the Alamo"). Oddly, whenever the story has him using a disguise for a long time as a major plot point, his voice is never disguised, despite him being able to disguise it during the short disguises in other episodes. Another oddity is that Dudley can never tell when the Chameleon is disguised or what he is disguised as, despite him having the sharp nose of a bloodhound (possibly the Chameleon can disguise his smell, too). If the Chameleon is splashed with liquid while in disguise, his suit will short circuit and he will be forced to return to normal. Also, his suit is wired into his brain and if it's removed, he will have no choice but return to his normal form.