A giant with a hundred eyes, who was also called Panoptes (all-seeing). Hera put him to guard Zeus mistress Io, but Zeus sent Hermes to kill the giant. Argus was then transformed into a peacock.
Odysseus dog, who was the only one to recognize him on his return to Ithaca, was also called Argus.
The builder of Jason's ship Argo also had the same name, and was one of the Argonauts.