"A creature born from the bloated core of a dead Haunted." - In game quote (in game Model Viewer).
The Cadaver could represent Ruvik's unwillingness to die, existing long after his supposed death at the hands of MOBIUS just as the Haunted's bodies are being recycled into new monsters.
They could also represent Ruvik's antisocial animosity to others, their attraction to sound and self-destructive aggression to the source of that sound much like Ruvik's behavior as "a serial killer masquerading as a scientist."
Since Cadaver is blind it will rely on sound to hunt player and other enemies. Normally they will either feast on a corpse of a Haunted or roam freely while glowing white. If Cadaver is alarmed it will turn yellow and move towards the source of the sound. If it hears the player, Cadaver will turn red and aggressively move towards the player, and if player won't escape in time, Cadaver will explode, killing them.
- Cadaver is Latin for corpse.
- In the cemetery in Chapter 2 it is possible to trick Cadaver into killing a Haunted. Doing this will earn the player the achievement/trophy "Death Trap".
- Art of Evil Within reveals that Cadaver was originally planned to appear in the main game and was going to be called The Bridge.