Phocus is a character in Greek mythology. The bastard son of Aeacus, the king of Aegina, and a sea nymph, Phocus's name comes from the greek word phoke, meaning "seal", because that's the form his mother took while trying to resist Aeacus's advances.
Phocus shared his father's attentions with his two legitimate brothers Telamon and Peleus, who later become Argonauts and the fathers of Ajax and Achilles, respectively. One day - history does not agree whether it was by accident or on purpose - Phocus was killed by his brothers while playing sport (in most stories a quoit but in more gruesome retellings by javelin.)
Phocus himself had one son, Panopeus, who appears briefly in the Iliad as a friend of the great soldier Amphitryon.