Phobos (Greek for "fear", is the root word of phobia) is one of the sons of Ares and Aphrodite in Greek mythology and the twin brother of Deimos. He is known as the god of fear, panic, flight and battlefield rout. He went with his father into battle, driving his chariot and spreading fear in his path. As a son of Aphrodite, goddess of love, each twin also represented the fear of loss.
Phobos Facts for Kids. Kiddle Encyclopedia.