Inuyasha is a half demon- his mother was a human, and his father is a dog demon. Inuyasha was pinned to a tree by one of Kikyō's sacred arrows for 50 years. Inuyasha is 15 years old (in appearance).
Inuyasha is a dog-demon. He's a half-demon, actually. His father is a big and well known dog yōkai (demon) and his mother a noble woman.