Phobos (Ancient Greek: Φόβος, pronounced [pʰóbos], meaning "fear") is the personification of fear in Greek mythology. He is the offspring of Aphrodite and Ares. He was known for accompanying Ares into battle along with the ancient war goddess Enyo, the goddess of discord Eris (both sisters of Ares), and Phobos' twin brother Deimos (terror).
In Classical Greek mythology, Phobos is more of a personification of the fear brought by war and does not appear as a character in any myths. Timor or Timorus is his Roman equivalent. In Roman mythology, he has also been referred to as Pavor.
Phobos is the son of Aphrodite and Ares. This may be seen in Hesiod’s Theogony, "Also Kytherea Aphrodite bare to Ares the shield piercer Phobos…" (Atsma). Ares was accompanied in battle by his sister Eris, Phobos, and Deimos. Phobos’s genealogy is shown:
Those who worshipped Phobos often made bloody sacrifices in his name. In Seven Against Thebes by Aeschylus, the seven warriors slaughter a bull over a black shield and then "touching the bull’s gore with their hands they swore an oath by… Phobos who delights in blood…"(Atsma). Ares’s son, Kyknos, "beheaded strangers who came along in order to build a temple to Phobos (fear) from the skulls." (Atsma).
Warriors and heroes who worshipped Phobos, such as Heracles and Agamemnon, carried shields with depictions of Phobos on them.
Because Aphrodite was their mother, Phobos and Deimos were gods of the fear of loss.
Hesiod depicts Phobos on the shield of Heracles as "…staring backwards with eyes that glowed with fire. His mouth was full of teeth in a white row, fearful and daunting…" (Atsma) and again later during a war scene as being "…eager to plunge amidst the fighting men," (Atsma).