He's a good boy, but not quite the cop biting champion. Some people in the tags already mentioned Negro Matapacos, the riot dog from Chile.
And the very term riot dog seems to have been coined for the local strays that participated in Athens protests from around 2008, that haven't been mentioned yet. Most famously Kanellos and Loukanikos (who looked very alike and it was only made certain they were different dogs after Loukanikos passed, so I hope I got pics of both).
Loukanikos would join every protest and stand with the protesters on the picket lines, would get kicked and tear gassed by cops, and apparently: "In September 2011, on the occasion of a striking policemen's union marching in the centre of Athens, he was 'initially confused' between two opposite sides, both of uniformed policemen, but when the riot police contingent attacked their striking colleagues, the dog sided with those who were being attacked."