This plush is called the "Sonic StickerBomb Plush".
It's supposedly an Amazon item (Did it sell out and is gone now?) but what company is producing it? It's a new take on plush to be sure, even if the name isn't 100% right. It has nothing to do with stickers, but the fabric used for the blue part is covered in character graphics. It has a blue background, but you can see Sonic, Knuckles, rings, and possibly some shapes there are part of the busy pattern. The rest of the doll is normal, with embroidered details & what looks like an ok head/face shape.
The feet are a little small, as are the hands, but it seems fairly ok otherwise. It's an interesting if 'trendy' thing to do for a plush, to make a character out of busy-character fabric. It doesn't look terrible though, and would certainly be unique to add to the collection...if you could find it for sale somewhere.