Nanco Nancy makes prize plushes in various sizes, but only in 2014 did Knuckles start to appear on their line up. Sadly, they didn't do that great of a job. The 10 inch size at left has open hands / mittens, which is interesting because usually all dolls use the fist only. His spikes are a bit under-stuffed, & they use a 'fin' of fabric instead of crafting his eyebrows. The white crescent is sewn on neatly. His proportions would be decent if he wasn't so wrinkly/under-stuffed.
At right is the 7 inch size. Despite being only a little smaller, this doll is terrible!

They tried flat felt strips for the spikes (fails) as well as his eyebrow ridge. The mouth line is too heavy & the under-stuffed fists look bad. His nose isn't THAT awful, it's just been understuffed & smashed sideways in the photo. The eyes are embroidered on.