Appearing only in "Do You Know Who You Look Like?", the Ancient Spaceman Bookstore is a bookstore under Carabas' ownership. The building contains books about aliens, and a group of alien believers named Ancient Astronauts Society gathers at the bookstore. After Carabas repeatedly impersonates Steve and leads many people astray, Steve exacts revenge on the impersonator by giving a false lecture to the Ancient Astronauts Society to Carabas' disapproval. As tensions between the two professors escalate and they prepare for a fight, a third party enters the bookstore as well as the fight, during which Steve prompts the third party into killing himself as well as Carabas.