In Greek mythology, Argus (Ancient Greek Ἄργος) is the eldest son of Phrixus and Chalciope at Colchis, grandson of Aeetes. With his brothers Phrontis, Melas, and Cytisorus he sails toward Orchomenus, meets the Argonauts, returns to Aeetes' court, and helps win Medea's aid — distinct from Argus son of Arestor who built the Argo.
Adapted from Wikipedia, "Phrixus" · CC BY-SA 4.0
I.Son of Phrixus
Phrixus, settled at Aeetes' court, marries Chalciope and fathers four sons — Argus (oldest), Phrontis, Melas, and Cytisorus — who later join forces with the Argonauts. Apollodorus and Apollonius have the brothers leave Colchis by ship to claim Athamas' wealth at Orchomenus; they meet Jason's company (at Circe's isle in Apollonius) and turn back with them to Aea.
Argus speaks for the brothers before Aeetes and begs Chalciope to win Medea's help lest their grandfather destroy guests and kin together. When the fleece is taken they flee with the Argo.
II.Homonym care
The atlas keeps argus-colchis strictly apart from argus-arestor (the Arestorid shipwright of the Argo), argus-panoptes (Hera's watchman), argos-dog (Odysseus' hound), and argus-eponym (the Argive city founder).