In Greek mythology, Argus is a giant with a hundred eyes. After Zeus had changed his lover Io into a heifer to protect her from the wrath of Hera, Hera demanded that the cow was given to her. She then charged Argus with the task of guarding it.
Argus was lulled to sleep by Hermes who then killed him, as Zeus had ordered him to do. Hermes brought Io back to Egypt, where she returned to her human form again. After Argus' death, Hera placed his hundred eyes on the tail of the peacock, her favorite animal.