Surume

The Kraken is a massive octopus creature from Norse mythology said to have dragged dozens of sailing vessels down into the ocean and devour its passengers. Indeed, when the Straw Hats first encounter one on their way to Fishman Island several crushed pirate ships can be seen between its massive tentacles; indicating that they feed on the ships and crew they pull down. Caribou recites a story about it, calling it "the enemy of the human race" and that it "never knows satisfaction where killing is concerned." However, Luffy apparently doesn't consider the one they encountered an actual threat, as he stated that he is going to tame it and refers to it as "that little guy" - despite the fact that the Kraken in question is at least several hundred times larger than the Thousand Sunny.