Dr. Balthazar is Frylock's friend discovered through use of the Buddy Nugget. He is a "creepy scientist guy" who is confined to a wheelchair and resembles a bald-headed crocodile or dinosaur man of some kind.
He is mentioned by Frylock to be "afraid of sunlight" and sports "metal teeth" with which he can apparently project an energy beam something like Frylock's laser eyes, although more powerful, which he uses to blow apart the walls of a club on one occasion when Frylock was unable to do so.
Although Frylock found him through the Buddy Nugget and thus apparently shares many of the same interests and personality traits, he is embarassed by Dr. Balthazar's rather murderous nature and obsession with finding the people who harassed him in high school and "killing their pets". After Balthazar blows a security guard's head off with his metal teeth beam after Frylock asks him if he's capable of using it to "change the guard's mind", Frylock abandons him, promising falsely that he'll email him at some point.