Based on the trailers we've seen so far, the upcoming Sonic the Hedgehog movie is all about the blue blur. The only other characters we've really seen featured so far are the human ones. This includes a sheriff played by James Marsden and the evil villain Dr. Robotnik who is played by Jim Carrey.
According to the Twitter account Sonic Paradise and further confirmation from Tails' Channel, there might actually be other characters in the movie, more like the anthropomorphic hedgehog. This information comes from the Paramount Spain Twitter account, which has supposedly lifted the lid on a rumoured owl character named Longclaw.
Tails' Channel followed this up by stating it could "independently confirm the name and existence" of the new character.
So, who is Longclaw and what does it look like? It's believed to be a minor character. Some diehard Sonic fans think it might be the son or a younger version of Old Man Owl – an owl who appeared in the 1996 Sonic the Hedgehog animated movie (see above). And then, there is the possibility it's an entirely new character.
Of course, it's probably best to consider this as some enthusiastic fan speculation until we get a proper confirmation.