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
The Simpsons episode guides a list and brief description of "The Simpsons" shorts from "The Tracey Ullman Show", a list of times Homer has said "D'oh!", and a list of Itchy & Scratchy cartoons. On two pages there are short biographies of each of the five immediate members of the Simpson family, namely Homer, Marge, Bart, Lisa and Maggie. Short biographies of other "Simpsons" characters appear in sidebars to each episode's page, starting with Santa's Little Helper for "Simpsons Roasting on an Open Fire" and ending with Willem Dafoe's Commandant from "The Secret War of Lisa Simpson". "The Simpsons Forever!: A Complete Guide to