Talos was created when Zeus fell into lust with a woman named Europa, a Phoenician woman descended from the nymph IO. In order to seduce her, he transformed into a white bull and blended in with her father’s herd. When Europa went to the fields to pick flowers, she noticed the white bull and pet it. The bull was so friendly, she decided to hop on its back for a ride. Zeus took off to the sea with her in tow, transformed into a swan, and swam to the island of Crete. Upon arriving they had sex and he made her the first queen of Crete. Zeus then made the constellation Taurus to commemorate the happy occasion.
Crete had an issue with pirates, so when Zeus left the island, he left the bronze giant Talos behind to guard the island as either a gift to Europa or to Minos. Talos was forged by Hephaestus or Cyclopes or Daedalus. Whoever designed him included a major flaw, probably so he wouldn’t be a threat if he ever became self aware. He only had one vein running through his entire body neck to ankle(Percy Jackson fans, remember this?) bound shut by a single iron nail. He circled the island three times a day searching for anything amiss. If he saw any unauthorized ships approaching the island, he threw rocks at them until they either sank or went away. When he threw rocks at the Argo, Media either cast a spell on Talos to calm him down and removed the bronze nail herself; or tricked him into doing it himself with hypnoses or mind control; or drove him so crazy with drugs that he removed the nail to end his misery; or she used keres to drive him crazy to the same end.
Keres are female death spirits descended from the goddess Nyx. The were “dark beings with gnashing teeth, claws and a thirst for human blood” (cool quote wikipedia). They would scour battle fields in search of wounded or dying warriors. They may be related to Valkyries (related as in the same thing mythologically, not blood related, obviously).
Anyway, no matter how the nail was removed, all myths conclude Medea somehow removed it. All the ichor bled from his body and he died, allowing the Argo to sail on.