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 makes his first and only appearance in "Buddy Nugget".
He is mentioned by Frylock to be "afraid of sunlight" and sports "metal teeth" with which he can apparently project an energy beam similar to Frylock's laser eyes, although much more powerful, which he uses to blow apart the walls of a club 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". When 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, falsely promising that he'll email him at some point, with the clear intention of never speaking to him again.
He briefly comes back to ask if that was Flavor Flav or the Chocolate Rain Guy leaving in a limousine but says that either way he's a big fan of both.