Festive Elf
The Festive Elf is a RARE pet that was obtainable from the Christmas Tree Egg (3% chance of hatching) and Egg of Many Gifts (80% chance of hatching). It was only available during the Christmas Event 2021.
The latest Pet Simulator X value list for Festive Elf can be found below:

Regular
💎 250,000 (250k)

Golden
💎 620,000 (620k)

Rainbow
💎 2,000,000 (2m)

Dark Matter
💎 6,000,000 (6m)