David Letterman passes Sarah Silverman the Stupid Pet Tricks torch and shares with her a very special Top Ten List. Also, Sarah meets the SPT staff and smooths out some unexpected intra-office issues. On stage, Sarah welcomes a former rodeo clown and his shockingly agile best friend, a goat who can walk on two legs, a party animal that really knows how to get down, and a dog that's up there with the smartest animals in the world. But only one will take home the title of Stupidest Pet Trick of the Week!