Robot & Monster focuses on the day-to-day adventures of Robot Default, a genius inventor, living with his roommate Monster Krumholtz, a cheerful and enthusiastic purple creature, and their pest-turned-pet Marf.

The duo work at the Blinking Light Factory, owned by Robot's snobby older brother, Gart, who loves to make his little brother as miserable as possible; as well as run-ins with their neighbor Ogo, who is obsessed with the both of them.