The Sea Devil was a giant octopus that guarded the Shrine of the Sea Devil and the pearl-inlaid Easter Island-like statues inside. Indiana Jones, Captain Whitby, Caspar Zzyzx and the crew of the Julie Anne encountered the creature on January 11th 1935 just as the crew mutinied under First Mate Turps. In the middle of the mutiny, the Sea Devil attacked the ship and killed its crew. Turps was killed when he tried to defend himself with a hand grenade. The Sea Devil was driven off or killed by the blast, the ship sank, and only Indy, Whitby and Caspar survived the encounter.
Later that same year, Jones would be forced to fight off a kraken which shared similarities with the Sea Devil.