When Buddy Baker first got his powers from a crashed alien spaceship, the Living Nightmare was inside. After Buddy stopped a bunch of escaped circus animals, he and his friend Roger Denning came across a creature that they assume came from the ship that gave Buddy his powers.
The alien seemed to have similar animal mimicry powers as Buddy, which ultimately proved to be his downfall. Since he uncontrollably mimicked nearby animals, Buddy sent Roger to go buy a pet mouse from a pet store and the two confronted the Living Nightmare next to a cliff. As Buddy expected, the creature mimicked the mouse's cowardice and dashed off a cliff to its doom.
Years later, the alien appears as a member of the Parliament of Limbs, the metaphysical group of previous avatars of the Red, the power source made of the life web that bonds all life and which empowers animal mimickers. He explains that Buddy's origin was a ruse by the Red using the trappings of the recently started superhero trend to create a new champion of the Red to protect the new Avatar: Buddy's daughter Maxine.