This is a 7 foot Sonic!
He's giant, because he was a part of a retail store display in the 1990s. (Thought to be Best Buy, write in if you can confirm this!) He's a relief figure (not fully 3D, but not flat) made of plastic. It's possible parts of him were hand painted. See how the color is uneven? He is likely discoloring with age. At right, you can see a Mario one was made in similar size/ format. They were likely displayed together by hanging on a wall in the store. There are likely only as many of these as there were stores at the time.