Term made by some lonelylooser who had no life and was waiting for his porn to load.
The creator of the term Peta-phile Has nothing better to do than sit around on his soggy Gelatinously Fat Buttox and slash an organization he knows nothing of.
Someone who loves their pets more than human beings or, at the extreme, someone willing to kill a human to save a lower animal's life.
Billy Ray blew-up the cosmetic test lab, killing several employees, in order to discourage the company from testing products on lab rats and hairless beagles. He was a total petaphile.