Dr. Rainbrain is a mad scientist who appeared on Sesame Street in a sketch with the Count.

The doctor and the Count have spent days and days building the Transylvanian Rocket Ship, and have just completed their work. When they count down, the rocket ship doesn't blast off, which makes the Count count down again in "Transylvanish," causing Dr. Rainbrain to go insane. At the end, the Count counts "One crazy scientist!"