Captain Clark is a unique "Still Life" entity—a warped, physical manifestation created by the Backrooms. The entity's appearance is derived from a local television commercial for a failing furniture store called Cap'n Clark's Ottoman Empire, in which the real human Clark dressed up in a cheap pirate costume with a peg leg. The Backrooms duplicated this concept, mutating it into a towering, grotesque creature standing over seven feet tall, with a literal chair or table leg fused onto its body as a peg leg, and a shoe fused into its lower back. Because the Backrooms warps time and space, the entity existed inside the labyrinth and was actively hunting ASYNC researchers even before the real Clark ever physically fell into the complex. In the climax, the human Clark attempts to "tame" his doppelgänger, believing they share a mutual peace, but the monstrous Captain Clark turns on him, brutally mauling and killing his human counterpart. The creature is ultimately subdued and taken into an ASYNC research facility to be studied as a specimen.

