Gamera vs. Guiron or Attack of the Monsters (ガメラ対大悪獣ギロン Gamera tai dai-akujū Giron) is a film directed by Noriaki Yuasa.
, also known as Attack of the Monsters and Gamera vs. Guiron, is a 1969 daikaiju eiga (giant-monster movie), the fifth entry in the Gamera series. It was one of five Gamera films to be featured as episodes of movie-mocking television show Mystery Science Theater 3000. It is currently in the Public Domain. This film's antagonist, Guiron (named for "guillotine"), is a giant quadrupedal dinosaur-like monster with a head shaped like a long knife, which is 100 times harder than diamond. Along the knife is a hole that shoots small magnetic shuriken. It also has the ability to fly.