He has the same hair piece as Dr. Inferno but in white and lime green as opposed to black and orange.
He has a similar torso to Dr. Inferno, except it is black, has no robotic arm, and has slime oozing down from the top of the suit.
It is possible that he is Slime Face, as in 8636 Mission 7: Deep Sea Quest he is wearing a diving suit, which the neck area is covered in slime. This can be concluded because Dr. D. Zaster has the same head as Slime Face.
His head is a printed, lime green-coloured translucent element.
In the LEGO Minifigure Sticker Collection Book , Dr. D. Zaster's description says "Dr. D. Zaster is an old friend of Dr. Inferno."
In the theme, Dr. D. Zaster is a friend of Dr. Inferno but in The Robot Chronicles he appeared as a battle-damaged version of Dr. Inferno