There are several characters in Greek legend using the name Argus/Argos. The following are the most notable.
Argus Panoptes (Argus the All-Seeing)
Argus is a giant with a hundred eyes and servant to Hera. His task was to guard a sacred heifer, but this heifer was actually a disguise of Io, a nymph whom Zeus favored. Zeus had plans to mate with Io in order to bring about a new lineage to thwart the Gods.
Argus often slept with several eyes open but he failed to prevent Hermes from the spells which he cast, a task Zeus ordered. Hermes was able to slew Argus.
Argus, Son of Arestor
Argus is often noted for being responsible for the construction of Jason and The Argonauts' ship, Argo.