Argus Panoptes, often referred to simply as Argos, is the figure in Greek mythology who possesses 100 eyes.
Argos, a giant, was tasked by Hera with guarding Io, a priestess of Hera who had been turned into a heifer by Zeus. His many eyes allowed him to watch Io constantly, making it nearly impossible for Hermes, sent by Zeus to free her, to sneak past him.
Hermes eventually lulled Argos to sleep with stories and music, then killed him. In honor of Argos, Hera then placed his 100 eyes onto the tail of her sacred bird, the peacock. This is the mythical explanation for the peacock's distinctive plumage.
