Santa's Little Helper and is the center of the plots of several episodes. During the course of the show, he has fathered litters of puppies, passed obedience school, had surgery for bloat, replaced Duffman as the mascot for Duff Beer, and been trained as a police dog at Springfield's Animal Police Academy. Some of the episodes that focus on Santa's Little Helper have been inspired by popular culture or real experiences that staff members of the show have gone through. Although cartoon animals are often anthropomorphized, Santa's Little Helper generally exhibits canine behavior. Cast member Dan Castellaneta currently provides the dog's sounds on
Bart's Dog Gets an "F" shorts, the characters spun off into their own half-hour prime-time show on the Fox network named "The Simpsons". Matt Groening, the series' creator, wanted Ullman to make a guest appearance in one of the shorts, but was told that she was too busy with the rest of "The Tracey Ullman Show". When her show was canceled in 1990, Ullman agreed to do a guest appearance on "The Simpsons" after being asked by Groening once again. The animal noises for the episode, including those by Santa's Little Helper, were performed by Frank Welker. It was the first "The Simpsons" episode Welker