Wylie Burp is a Great Dane of the Wild West among the animals of America, who in his day kept the law enforced in Green River, defeating the Cactus Cat Gang. Fievel idolizes him, and he is one of the reasons Fievel is so eager to move out west. And when Fievel discovers Cat R. Waul's plot to turn the mice of Green River into mouseburgers, Wylie Burp becomes Fievel's final hope. But, when Fievel finally meets him, Wylie is a shell of his former self; an over-the-hill, down and out drunkard whose spirit had been broken. But Wylie is so taken by Fievel's determination, that he offers to teach a younger dog to be tough, and to be the new law in Green River. Fievel didn't know any dogs, so they settled for Tiger. Wylie trained Tiger until he was tough enough to take on and defeat Cat R. Waul and his gang, saving the mice. At the end of the film, Wylie Burp presents Fievel with his very own sheriff's badge, in thanks for helping him out of his rutt. When Fievel begs to differ, stating that he wasn't really a hero, Wylie tells Fievel that he himself was the hero he was searching for all along.
Wylie is strangely absent from the television series Fievel's American Tails, but appears as a main character in the video game An American Tail: Fievel's Gold Rush, in which he left Green River to go prospecting for gold, but gets captured by Cat Malone and his gang of claim jumpers, leaving Fievel to find pieces of the map to his secret gold mine.
"I'm tired of leading a dog's life and fightin' like cats and dogs against cats and dogs, a young pup's doggin' my trail tryin' to become top dog. I'm going to the dogs in a dog eat dog world, son."
- He was voiced by the late James Stewart, in his final film role.
- He is loosely based on the famous Wild West hero Wyatt Earp.