Ernie the Giant Chicken

A chicken who holds a grudge against Peter Griffin on Family Guy. His rivalry with Peter stemmed from him giving Peter a bad coupon in "Da Boom", following which they had a long, destructive fight (the grudge may go back to Peter bumping into him during a dance in Episode 98, Meet the Quagmires). Since then, Ernie has appeared on four occasions, most recently in "No Chris Left Behind", where his name was revealed to be Ernie and it was shown that he has a wife named Nicole. His fights with Peter are very elaborate and destructive. Peter has won every fight to date and at the end of each fight, Peter assumes him to be dead, only for Ernie to show some sign of life, implying that he and Peter will fight again. Ernie's appearances are often random, with him tackling Peter out of nowhere or staring at him through a window mid-conversation. After the fights are over, Peter returns to what he was doing, injuries and all, as if nothing happened.

Source: Wikipedia.org