Dr. David Commerdinger, hired about a year ago by the Seattle Police Dept. as a forensic chemist, is a 5' 8" Caucasian man with broad shoulders, excitable blue eyes, red hair worn in a flattop style and a handlebar mustache. When he's himself, at least. Which, while undercover on this assignment, seems to be never.

As "Dr. Joseph Bringle," his first undercover identity, he is apparently a junior professor at the University of Seattle in the Chemistry & Physics dept. He's even on their website, although not assigned to teach any courses.
Joseph has short, grey hair (from a bottle of course), and David's mustache was cut down to just being over his upper lip rather than a handlebar.

His third identity, the tramp clown Hoblow Joe, is who he is on a reality television game show. Sad, woebegone, costumed in much-patched dark garb with no bare skin showing anywhere, Hoblow Joe has one significant difference in appearance from David's other identities which isn't makeup or costuming: His eyes are no longer blue, but a peculiar shade of deep grey. The whites of his eyes are darkened and murky. To those few in the know, the tell-tale eyes of someone with a super-power.