Remember the Be@arbricks? This one is certainly official. Be@arbrick is by Medicom.

Bearbricks are blind-boxed (as seen here) so you could get any of the ones shown at left.

The Sonic one is decent looking enough, for something styled onto an oddly shaped 'bear'. Notice the clear portion of the ears to support his triangle shaped ones. He comes with the card seen above, which notes this as a 20th Anniversary item. Is the word "Hero" written in the "Oreo" cookie font? (and if so, why) The site for BearBrick is: http://www.bearbrick.com/
Price: Series 23- Set of 12 random figures: $90 - $110
Individual figure: $8 - $15
So they're pretty expensive. You can also look in hobby stores online & off, as well as Ebay if you're after just 1 of the figures. (highly likely, in the case of sought-after Sonic here) The figures are about 2.8 inches tall. Info & photos from Static-the-Hedgehog