don-chan_(usada_pekora)
"Wait... that's not a muffler. Luna-san, you don't know the name of Pekora's friend?"
-Houshou Marine, 2020
Don-chan is a mysterious, perpetually inexpressive rabbit-like creature that spends most of its time complacently wrapped upon virtual YouTuber Usada Pekora's neck. In Pekora's prisoner outfit, it's instead wrapped around her right leg, holding a carrot-shaped ball and chain with its mouth.