>>3121048But him having a bird head doesn't add or take away from him shadow summoning (as far as we know?). Seems to me like having a rock FACE or bird FACE that has nothing to do with your quirk, is like having brown hair or green eyes. With 80% of the world's population being all modified in someway, looking weird isn't part of the quirk.
So to answer
>>3121032, I'm going to say his quirk is the animal talking thing, but from his family, he just got the DNA to look like a rock....but it's still early. We're going to find out later that the characters with two quirks are going to be the mega key to some plot later on.