El Señor al Diente

El Señor al Diente is a black-and-white tooth who "fell into" El Llamafante’s planet, the Egg.
He hates colors and wants to destroy the Egg. He smokes cigarettes, and through the smoke, the colors slowly disappear. 

But in the end, El Llamafante realizes that it was his own tooth all along—and that he must accept his own dark side.

"I’m aware that the line between good and evil goes through my heart too."