"Bring me the head...of Sonic the Hedgehog!"
This is probably something Eggman would say, and now well...it seems it can be done, with this strange selection from Target. Presumably, this is a Jakks Pacific item?? (Subject to correction) It may appear in the Kids Bedding area OR the Electronics/toys area of the store. Here, it is seen in the electronics area. It's pretty big too!
It's also pretty nicely done...the green for the eye is too small, and the highlight is at the bottom rather than the top, which looks rather odd. But the face proportions, fabric choice, ears, spikes & general structure are surprisingly good. But like...why JUST his head? You can't even use it as a cushion? It'll roll away? It's kind of creepy to have a chopped off head? It being well-structured actually makes it sort of worse? What an odd thing to find in 2021. 

In the galalry are the factory photos from Club Mocchi for the 15 inch character head pillows / cushions. With this, now you can see that there's a Tails head that will be released as well. 

Seeing the head raises a few questions like, why did they get Tails' eye-shine-dot right and then get it wrong for Sonic? Why is his eye color thick/more correct & Sonic's overly-thin? Then, the Tails ears show that they can make a 3D ear, but they left Sonic's as flat/floppy flaps. They also used stuffing for the face-edges & bangs (instead of felt/etc) so why not let Sonic have normal ears if they know they can make the effort. The Tails head is pretty cute, though the bottom of it is overly...slim? Like it tapers down strangely in the back?
Not sure about how it would look with the 2 character heads just tossed onto the gameing sofa like throw-pillows...but they're likely to be a Fall 2021 release, at about 35 dollars each.