Santa's Little Helper of their sacrifices and starts treating him badly, causing him to run away. He ends up in the possession of Mr. Burns, who trains him to become a vicious attack dog. Several days later, Bart stumbles upon the trained Santa's Little Helper and is attacked, but the greyhound eventually recognizes his old friend and stops. In "The Canine Mutiny" (season eight, 1997), Bart uses a fake charge card to buy a well-trained rough collie named Laddie from a mail-order catalog. Laddie learns many tricks that Santa's Little Helper is completely unable to perform, and the Simpson family nearly forgets about
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