Ghoul Horse
The Ghoul Horse is a MYTHICAL pet that was available from the Eerie Egg and the Cursed Egg for a limited time. It was also sold by the Traveling Merchant. It was available in the Halloween 2021 Event.
The latest Pet Simulator X value list for Ghoul Horse can be found below:

Regular
💎 562,000 (562k)

Golden
💎 1,600,000 (1.6m)

Rainbow
💎 4,700,000 (4.7m)

Dark Matter
💎 21,400,000 (21.4m)