There's no sure way to tell, but from the looks of it, Kong the Pitbull is not a purebred. When asked whether the Hulk was a purebred, Marlon Grennan, the owner of DDK9 kennel, said yes he is and he can prove it by DNA testing. But to this day he hasn't. This suggests that Hulk isn't a purebred. Many experts conjecture that Hulk can be a cross between an American Pitbull Terrier and an American Bulldog. If this were true, then DDK9's Kong is not an American Pitbull Terrier since he is a descent of the Hulk. And because we can't say for sure whether Hulk is a Pitbull or not everything becomes confusing. So, at the end of the day, we can't say for sure.