Clash of the Titans is an American 1981 Fantasy–adventure film involving the Greek hero Pereus. It was released on June 12, 1981.thumb|300px|right
King Acrisius of Argos locks his daughter Danea away from mortal men to avoid a prophecy that he would die if his daughter had a son. While she is imprisoned, the "good" god Zeus impregnates her. After discovering the pregnancy, Acrisius casts his daughter and her newborn son Perseus out to sea in a wooden coffin, hoping to kill both and avoid his fate. In retribution, Zeus not only kills Acrisius, but also orders the god of the sea, Poseidon, to release an ancient monster known as the Kraken to destroy Argos, fulfilling the prophecy. Meanwhile, Danaë and Perseus safely float to the island of Seriphos.
Calibos, son of the sea goddess Thetis, is a young man destined to marry Princess Andromeda, the daughter of Queen Cassiopeia and heir to the rich city of Joppa. But cruel and destructive Calibos has destroyed every living thing surrounding the Wells of the Moon, including Zeus's entire sacred herd of flying horses (except for Pegasus). As punishment for this and his many other transgressions, Zeus transforms Calibos into a satyr-like creature who is subsequently shunned and forced to live as an outcast in the swamps and marshes. Thetis, furious at her son's fate, vows that if Calibos cannot marry Andromeda, no other man will, either. Equally infuriated by Zeus's total devotion for his own son, Thetis transports Perseus from Seriphos to Joppa. Perseus, befriended by the scholar and playwright Ammon, learns of Andromeda and her plight: she cannot marry unless her suitor successfully answers a riddle, and any suitor who fails to answer the riddle correctly is burned at the stake. Perseus is armed with gifts from the gods (a sword, shield, and a helmet that renders its wearer invisible), and receives a message from Zeus on how the shield will one day save his life. Perseus captures Pegasus and follows Andromeda's spirit on her nightly journey to learn a new riddle from Calibos. Armed with the answer, Perseus is nearly killed by Calibos but escapes, losing the magical helmet in the swamps in the process.
Perseus appears at the next ceremony for a new suitor and answers the riddle correctly, presenting Calibos's severed hand (with a gold ring on one of the fingers, which is the answer to the riddle) and winning Andromeda's hand in marriage. At the temple to Thetis, Calibos prays to his mother Thetis to take vengeance on Perseus. Thetis tells Calibos that she cannot do so because Perseus is protected by Zeus, but she can take vengeance on Joppa. At the wedding, Queen Cassiopeia compares Andromeda's beauty to that of Thetis herself, which angers the goddess and gives her an excuse to fulfill her son's wish. The statue of Thetis collapses and its head comes to life, demanding Andromeda as a virgin sacrifice to the Kraken in thirty days, or else Joppa will be destroyed.
Perseus seeks a way to defeat the Kraken, while Pegasus is captured by Calibos and his men. Zeus commands Athena to give Perseus her owl Bubo as a replacement for his lost helmet of invisibility. Instead she orders Hephaestus to build a mechanical replica of Bubo as an aid for Perseus. The new Bubo leads Perseus to the Stygian Witches, three blind women who tell him the only way to defeat the Kraken is by using the head of another monster, Medusa the Gorgon. Once a beautiful woman, Medusa had been punished by the goddess Aphrodite by being transformed into a horrible monster. Meeting Medusa's gaze will turn any living creature to stone, including the Kraken. She makes her home on the Isle of the Dead, which lies across the River Styx, at the very edge of the Underworld.
Once there, Perseus and his men battle Dioskilos, a two-headed dog that is the guardian of Medusa. One of the soldiers dies, but Perseus and the other two succeed in the slaying of Dioskilos and set forth into the ruins where Medusa resides. One of Perseus's men loses his life to one of Medusa's arrows, while the last becomes caught in the stare of Medusa and is transformed into a stone statue. Perseus eventually manages to not only deceive Medusa with the help of his shield, but also decapitate her with his sword and collect her head, but loses the shield in a pool of Medusa's acidic blood. As he and his party set to return, Calibos raids the camp, drives off the group's horses and punctures the cloak carrying Medusa's head using a three-pronged weapon he has replaced his hand with, causing her blood to spill and spawn giant scorpions. The scorpions and Calibos attack the party. After the last of his men are killed, Perseus is able to slay the remaining scorpion and manages to best Calibos, whom he finally kills with Aphrodite's sword.
Perseus, weakened by his struggle and running out of time, asks Bubo to find Pegasus. The owl locates Pegasus in the swamp, guarded by Calibos's men and the vulture. Bubo manages to scare them off, destroy the camp, and free the winged stallion. Just as Andromeda is about to be sacrificed to the Kraken, Bubo appears, trying to stall the Kraken while Perseus catches up flying on Pegasus. Perseus approaches the Kraken, but is knocked off, falling into the ocean. Bubo retrieves the head and delivers it to Perseus, who frees the head, turning the Kraken into stone which collapses into the bay. Perseus throws the head into the ocean and frees Andromeda. Pegasus emerges from the sea to the crowd's delight.
The gods discuss the outcome of the adventure: Perseus and Andromeda will live happily, rule wisely and produce good children. Zeus forbids the other gods to pursue any vengeance against them. In addition, the likenesses of Perseus, Andromeda, Pegasus and Cassiopeia are set among the stars as contellations to forever remind mankind of the values of heroism and bravery.