Film: It Came from Beneath the Sea (1955)
Location: Ocean/Civilized area
Height/Weight: About as large as one of the support towers on the Golden Gate Bridge.
Summary: Out of all the creatures in the sea, none is a bigger enigma than the octopus. Despite having no bones to speak of, they somehow outwit, outplay, and outsmart just about any other predator in the ocean. But sometimes, it's okay to throw away these gifts when size matters. That's what one octopus thought, at least.
History: A slumbering yet foul-tempered giant octopus somewhere in the Philippine Trench, this beast got a rude awakening when H-bomb tests rendered it radioactive and unable to attract its natural food sources. Naturally, the cephalopod took the reasonable approach and proceeded to try and absolutely wreck the piss out of the ones who had ruined it. And all their defenses only made it angrier, especially all that godforsaken electricity!
Notable Kills:After slapping a city block with its tentacle, everyone on it is squashed flat. Then again, if they got squashed, then why don't their corpses show up on the tentacle? Unless those suction cups on it are actually...oh no...
Final Fate: After being neutralized by a jet torpedo, a second torpedo is shot at the octopus's face, destroying it.
Powers/Abilities: Immune to radiation and most artillery.
Weakness: A weapon of significant force must be fired at it at point-blank range.
Scariness Factor: 4-While it couldn't get too far beyond dry-land, the destruction that this monster caused is undeniable. And Heaven help you if you happen to be at sea...
Trivia: -Due to budget constraints, Ray Harryhausen could only afford six arms on his octopus rather than eight, essentially making it a "Seispus", or as Ray plainly called it, a "Sixopus".
-The largest octopus in the world is the Giant Pacific Octopus, which can measure more than thirty feet in length.