The cape-like part of its shadow lifts a moment, then falls again.

Fawkes says, "I saw some of them made. They happened when a human and another human, or sometimes another creature altogether, were thrown into the vats in Vault 87 together. The virus fused them together into monstrous hybrids. The few who lived were in constant pain, and could not speak."

Something brighter comes into the red gleam, and the creature attempts to stand up straighter; it must be a good seven feet tall...