Omni-Man, known by his civilian alias Nolan Grayson, is the secondary character and the main antagonist of the comic and cartoon series Invincible.
Dubbed "the greatest superhero of Earth", Omni-Man is a humanoid alien of a race known as Vitrumites that was sent to protect the Earth from would-be invaders. He married a human named Debbie, who gave birth to his son Mark. In reality, he was sent by the expansionist and brutal Vitrum Empire to conquer Earth.