Phrontis (Ancient Greek: Φρόντις, "thought, care") son of Phrixus and Chalciope (Iophossa), daughter of King Aeetes of Colchis, is one of the brothers who meet Jason and the Argonauts and help in the quest for the Golden Fleece. He is distinct from Menelaus' helmsman Phrontis son of Onetor and from Phrontis wife of Panthous at Troy.
Adapted from Wikipedia, "Phrontis (son of Phrixus)" · CC BY-SA 4.0
I.Son of Phrixus
Apollodorus lists Phrontis among the sons Phrixus begot on Chalciope in the Colchian royal house — with Argus, Melas, and Cytisorus (and in some accounts Presbon). Hesiodic scholia and Hyginus preserve the same brotherhood.
Raised in Colchis, the brothers later set out in connection with their father's Orchomenian past; Argonautic epic finds them stranded or met on the voyage and drawn into Jason's enterprise.
II.With the Argonauts
In Apollonius' Argonautica Phrontis and his brothers greet Jason; once Jason learns they are grandsons of Aeetes he persuades them to return to Colchis and aid the taking of the Fleece, questioning them on the layout and security of the land.
After the Fleece is won, Phrontis and Argus leap ashore with Jason to clasp Medea's knees and beg rescue from Aeetes. The brothers then sail back toward Greece with the Argo's crew.
III.Homonyms
This atlas entry (phrontis-colchis) is Phrixus' son. Phrontis son of Onetor, Menelaus' helmsman slain by Apollo at Sunium, is phrontis-sparta. Queenly Phrontis wife of Panthous, mother of Euphorbus and Polydamas at Troy, is a third figure sharing only the name.