Simon Riley, also knows as "Ghost," is a British SAS operator that works alongside Captain Price, Soap, Roach and Gaz for the Task force 141. He's a mysterious man that conceals his face with a skull mask, he's a wraith hybrid.

He has blonde hair and brown eyes, six foot two tall, broad shoulders and an intimidating look, he can manipulate the shadows and become immaterial, but will poison himself if he uses his powers too much, and black smoke comes out of his body when using his powers.