The Cat-o-nine-tails is a character who only appears in the episode "Ghoul Fools." It is said by the ghostly crew to be their favorite pet while they were singing their song, "We're the Ghouls of the Briny Deep."
- The cat-o-nine-tails bears a resemblance to the Kitsune of Japenese foklore. however, Kitsune is a fox, not a cat.
- It also slightly resembles the Pokémon Ninetales, which is based on the Kitsune.
- Historically, a cat-o-nine-tails was a whip with nine ends used to punish sailors in the navy.