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 show. The celebration ended on January 10, 2010 (almost 20 years after "Bart the Genius" aired on January 14, 1990), with "The Simpsons 20th Anniversary Special – In 3-D! On Ice!", a documentary special by documentary filmmaker Morgan Spurlock that examines the "cultural phenomenon of "The Simpsons"". As of the twenty-first season (2009–2010), "The Simpsons" became the longest-running American scripted primetime television series, having surpassed "Gunsmoke". On April 29, 2018, "The Simpsons" also surpassed "Gunsmoke"s 635-episode count with the episode "Forgive and Regret." "The Simpsons" has won dozens of awards since it debuted as a series, including 31 Primetime Emmy