I'm trying to find a fanfic I read a couple of years ago. Eric Kirby is being chase by a velociraptor and falls into a tank of chemicals. When he gets out he's changed into a velociraptor himself. He ends up mated to the raptor that was chasing him. When his parents find him and realize he doesn't want to be human again, the get themselves turned into raptors to join him.

That's as much as I can remember right now.