Dr. D. Zaster is an old friend of Dr. Inferno and is also Inferno's scientist. He attempted to cover LEGO City in toxic slime, but his plan was foiled by Agent Chase. He is seen at the end of The Robot Chronicles. He rises out of the hole that Dr. Inferno fell in. He may be like Dr. Inferno's ghost. He only appeared in one set in Agents 2.0. He looks like Slime Face, though they have different legs, torsos, and hair. Their Faces are the same. It is unknown what happened too Dr. D. Zaster after Agent Chase foiled his plot. He was either arrested or killed.