After 31 years of mocking terrible films for the amusement of audiences, you'd think the RiffTrax/Mystery Science Theater 3000 crew would be out of bad movies. Instead, the RiffTrax guys keep turning up stinkers. RiffTrax Live: Octaman will see Mike Nelson, Bill Corbett and Kevin Murphy dogging the 1971 octopoid tragedy Octaman for a national audience at 7 p.m. Thursday, April 18, at the Marcus Wehrenberg Ronnies Cine (5320 South Lindbergh Boulevard; www.fathomevents.com). Writer/director Harry Essex's film is about an irradiated octopus man (created by special effects genius Rick Baker, then very young) who seeks revenge on the scientists who stole its offspring. Never before has a guy in a rubber suit with flimsy tentacles terrorized such a large audience. Tickets for the live broadcast are $15.67.