Nikki

Nikki is the mascot and assistant of Nintendo Letter Box/Swapnote and Swapdoodle for the Nintendo 3DS. Originally just being an ordinary Mii, she later would get many drawings of her when Swapdoodle, was released and from Nintendo Badge Arcade.
She is known for being Poppy's Discord avatar and has been since March 2022 to the current day, with the image of her changing each month, some themed to seasons. Pops has claimed, "I don't know why I suddenly just liked Nikki, I just remembered she existed and found a bunch of her official art and thought oh hey that's cute".
For the Halloween Extravaganza 2023, Poppy would attend the event dressed as Nikki, as by then, the whole LOM recognised the character and heavily associated them with each other. Pops would reveal their costume through a short trailer made just for the occasion, alongside Shmexi, Razza, and Kelloggs. A link to the costume trailer can be found HERE.