The Kraken is a Scandinavian Mythological Seamonster of tremendous size of strength said to exist off the coasts of Norway and Greenland. Its tentacles are large enough to be able to pull entire Ships under the Water and destroy cities with relative ease. The Creature possessed endurance to match its strength. In addition to its tentacles, it was also armed with gaping maw full of many sharp teeth. Originally, kraken were considered to be similar to giant crustaceans or colossal whales. However, in later versions, the descriptions changed to match those of a cephalopod - Squid or Octopus.
Clash of the Titans (1981)
The Nordic Kraken appears in the 1981 Film, taking the place of the actually Greek Cetus/Cetea. In this Movie it is the Pet of Poseidon and Zeus orders it to destroy Argos to punish Acrisius, the King of Argos, from casting his daughter Danae and grandson Perseus into the Sea. The Goddess of the Sea,Tetis, then unleashed it an the City of Joppa as excuse to punish Persues, Andromeda was offered to be sacrificed on Tetis decree as Poseidon releases the Kraken. Perseus slayed it with Medusa´s Head which turned it to Stone.
Clash of the Titans(2010)
The Kraken appears in the 2010 remake as an adversary of Perseus. The Kraken is seen in the beginning, when the Narrator explains Hades created it to slay the Titans. He was the tricked to rule the Underworld. It is assumed that Zeus forced Hades to lock up the Kraken so it wouldn´t harm anyone. The Kraken was released on Argos to destroy it, but Perseus slayed it with Medusa´s Head which turned it into Stone.