Argus Panoptes

Argus Panoptes, or Argus the All-Seeing, was a bizarre monster of colossal proportions who featured in Greek mythology.

Description
A primordial giant who never slept and was said to possess one hundred eyes - of which only half were closed at any one time, leading to his epithet of the All-Seeing - Argus was the faithful servant of Hera, the Queen of the Gods.

History
The greatest act that Argus performed in the service of the Olympians was to kill their great enemy Echidna, who had waged war upon the gods with her mate Typhon, while she slept alone in her cave.

Later, Hera would task Argus with guarding the white heifer Io from her husband King Zeus, who had designs on the beast. However, Zeus had Hermes, the Messenger of the Gods, visit Argus and put his eyes to sleep with a charm, before caving his skull in with a rock. Hera subsequently had her favoured servant immortalised in the eyes of a peacock's display.