Dr. Saturn is a character in EarthBound. He is a friendly Mr. Saturn, and the only known member of the species in Saturn Valley to not be named eponymously after its species. Dr. Saturn's home acts as the village's hospital, and here he will heal Ness' party free of charge. He will cure any status, including homesickness.
Dr. Saturn is just a normal Mr. Saturn with the only other physical difference being the blue trashcan he is in.