Wired goes long on MST3K:
Though MST3K boasted a remarkably talented writing staff, its real stars were the B movies that were riffed apart in each episode. The series would skewer all manner of films, from cheapo action flicks like The Pumaman (1980) to drecky sci-fi-horror amalgams like Night of the Blood Beast (1958) to creepy kids’ fare like Merlin’s Shop of Mystical Wonders (1996).
Hodgson: Film distributors would do this trick where they’d license you several movies. Half of them might be movies you’d heard of, and half were the movies we actually wanted, the B movies. We didn’t want the cocaine—we wanted the baby laxative they put in the cocaine.