Deimos (mythology)
In Greek mythology, Deimos (Ancient Greek: Δεῖμος, meaning "dread") was the personification of terror.
He was the son of Ares and Aphrodite. He is the twin brother of Phobos and the goddess Enyo who accompanied Ares into battle, as well as his father's attendants, Trembling, Fear, Dread and Panic. Deimos is more of a personification and an abstraction of the sheer terror that is brought by war and he never appeared as an actual character in any story in Greek Mythology. His Roman equivalent was Formido or Metus.
Asaph Hall, who discovered the moons of Mars, named one Deimos, and the other Phobos.
On the modern monument to the battle of Thermopylae, Leonidas' shield has a representation of Deimos.
Read more about Deimos (mythology): Deimos in Popular Culture, Deimos and Phobos in Sparta