Real Name: Unknown
Mutant Powers: Superhuman hearing and smell. In addition, he has a robotic optic for a right eye that gives him superhuman vision (and a zoom lens!) as well.
Voice Actor: Mark Gibbons
Guest Appearance: "Target X"
Back Story: None given. Gauntlet is an operative of HYDRA, a top-secret, non-government affiliated organization that does a lot of eeevil stuff. Anything beyond that is unknown. Gauntlet presumably died at the end of the same episode he was introduced in.
Personality: Gauntlet is another character that wasn't given a big part even in the episode he was a guest-star in; he only had 5 lines or so. As far as I can tell, Gauntlet takes pleasure in his job as an operative, is completely loyal to HYDRA, and has an extensive knowledge of gun technology. Anything beyond that is anybody's guess.
Final Reflections: Gauntlet was a pretty forgettable character in X-Men: Evolution, mainly because he only had a pretty minor role in only one episode. Heck, I'm an Evo fanatic, and I STILL keep forgetting this guy actually exists in this continuity. He DOES exist in the "classic" Marvel comics, though, so he's not a completely new character.
(Picture courtesy of Matt.)