William P. "Billy Hope" (also known as Billy Hope) is the quarternary antagonist of Outlast. He is the Walrider's first host.
He might believe that Rudolf Wernicke is his father, as his the one who kept Billy alive with the Walrider. He was in a sphere, possibly glass, with many tubes and instruments running into and out of his body. He is kept alive by the machine but Miles Upshur kills him by stopping the flow of fluids from the reservoir and turns off power to his machine, he bleeds out the machine rapidly. The Walrider then leaves Billy's corpse and has Miles as his new host.