The Ziff Who Came to Dinner/Gags

Couch gag

 * In a parody of Powers of Ten, the couch scene pans out until it reaches outer space, where the galaxies are replaced with atoms, which pan out until they reach Homer's head and then the couch scene again. Homer then says "Wooowww". (reairings and repeats of the couch gag in other episodes redub "Wooowww" with "Cool!" and have Kang and Kodos laughing instead of staying silent)