Deimos

In Greek mythology, Deimos (Ancient Greek: Δεῖμος, pronounced [dêːmos], meaning "dread") was the personification of terror.

He was the son of Ares and Aphrodite. He is the twin brother of Phobos and nephew of the goddess Enyo who accompanied her brother 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 - although the moons are very different and not twins like their namesakes.On the modern monument to the battle of Thermopylae, Leonidas' shield has a representation of Deimos.