The One-Eyed Black Cat was an unused character found in early concepts for the Haunted Mansion.
In an unused script for the Haunted Mansion the Ghost Host would have warned you at the beginning of the attraction of the "Unnatural and dreadful one-eyed back cat" claiming that he detests mortals, especially happy ones. In the attraction the cat would have would have appeared near the climax of the ride in the form of nothing more than a red and green cat eye which has the corpselike cat's head materialize around it with the empty eye socket having a red glowing dot inside of it, the cat's head would then transform into that of a screaming green corpse head. It is unknown how this effect would be achieved or presented. His eye could also be seen at other points in the ride, indicating the monsters's status as a mastermind behind the events of the whole house.
In the queue outside of Liberty Square's Mansion a carving of the cat is seen in the bottom right hand corner of the backside of the composer's crypt alongside many Rolly Crump inspired musical instruments. If you put your hand up against the carving cat it can be heard meowing.
- The Cat was to be a reference to Edgar Allan Poe's short story the Black Cat where a violent alcoholic man stabs out his pet cat's eye and hangs it only for another black cat missing the same eye shows up and drives him insane.
- The Cat's true nature in a Mansion-related context (had he been installed) is ambiguous. He may have been a ghost shapeshifting as a cat, the ghost of a cat, or even a demon that had never really been alive in the first place.
- Despite never being installed, the Cat has gained a significant amount of attention in the fandom in recent years, being an easy choice for a Mansion "villain" as opposed to most of the (benevolent) Happy haunts.
- The concept of the Cat's head turning into something resembling a human skull was later used for the Attic's Pop-Up Ghosts.