Elf Yellowy is a character in Anime Gacha, one of 5 winter elves (the others being Bluey, Greeny, Reddy, and Pinky), part of the Winter Holiday case. They have since appeared as a pet in many Lunime games that feature a studio or scene maker.

Elf Yellowy in Anime Gacha
Quotes
"IT'S THE BEST TIME OF THE YEAR!" - Elf Yellowy in Anime Gacha