Chief is an antagonist in Disney's 1981 film The Fox and the Hound and a minor character in it's 2006 midquel. He is an old irsh wolfhound,which is Amos Slade's older pet (who has the same eyebrows as he does).
Chief is a cranky and mean old dog with a short-temper until he reforms after he survives as he had a nice attitude and then he whimpered after Amos threatened him that he'll break his other leg.
Even though he is nice to Copper, he disliked him at the start of the film when his owner, Amos Slade brought him home, but he grew to like Copper.
He dislikes Tod, but in the end, he possibly learns that he wasn't a bad fox.