Talos

In Greek mythology, Talos (sometimes spelled Talus or Talon) was a bronze automaton tasked with protecting Crete from pirates and invaders. Though often depicted as a giant, no ancient text explicitly describes him as such.
Various sources offer differing accounts of Talos' origins and role. The most well-known version comes from Argonautica by Apollonius of Rhodes (circa 3rd century BCE). According to this myth, Talos was a descendant of the bronze race, born from ash-trees. He was a bronze figure, invulnerable except for a single vein in his ankle, which was protected only by a thin layer of skin.
Talos was given to Europa by Zeus to safeguard Crete, and he performed this task by circling the island three times each day. He encountered the Argonauts as they returned from their quest for the Golden Fleece. As the Argo neared Crete, Talos attempted to prevent their entry by hurling massive rocks at the ship. Medea, however, declared that only she could defeat Talos. Using her magical powers, she summoned the Keres (death spirits), causing Talos to scrape his ankle and allowing his life-giving ichor to drain from his body, which led to his death. Apollonius uses a metaphor in describing his demise, comparing Talos to a "monstrous pine tree" being felled, which could suggest he was larger than human size.
In the Bibliotheca of Pseudo-Apollodorus, various versions of Talos' origins, appearance, and death are presented. Some sources say Talos was part of the Bronze Race, while others claim Hephaestus created him and gave him to Minos. As for his form, he was sometimes described as a bull, other times as a bronze man. Pseudo-Apollodorus also details Talos' role as a guardian of Crete, circling the island three times a day. He had a single vein running from his neck to his ankles, sealed by a bronze nail.
Regarding his death, three versions are given. In two accounts, Medea is responsible: either she drove him insane with drugs, or, promising him immortality, she removed the nail from his ankle, causing his ichor to spill out. In the third version, Talos is killed by the Argonaut Poeas, who shoots him in the ankle with an arrow.