The song played when Santa's Little Helper looks for Homer in the maze is KoЯn's Freak on a Leash. The scene follows Santa's Little Helper's path; the video for "Freak on a Leash" follows the path of a bullet.
The last line of the show is Groundskeeper Willie after he adopted the python, saying, "That'll do, snake. That'll do." This is a parody of a famous line from the 1995 film, Babe.
The song playing in the background as Santa's Little Helper goes through police dog training is the theme from the 1970s crime drama series S.W.A.T.
Lisa suggesting that Santa's Little Helper barks for novelty Christmas records is a reference to Don Charles' version of "Jingle Bells" from 1955, popularized further through Dr. Demento's radio programs.