Talos

In Greek mythology, Talos was a bronze automaton whom Zeus gave to Europa. He was forged by Hephaestus and the Cyclopes. Europa took him to Crete and he stayed there, circling the island's shore three times daily while guarding it. He threw stones at any approaching ship.

Talos had one vein which went from his neck to his ankle, bound shut by only one bronze nail. The Argo, containing Jason and the Argonauts, approached Crete after obtaining the Golden Fleece. Medea cast a spell on Talos to calm him; she removed the bronze nail and Talos bled to death. The Argo landed.

Apollodorus. Bibliotheke I, 26; Apollonius Rhodius. Argonautica IV, 1638-93