Santa's Little Helper becomes a police dog while Bart gets a pet snake.

!! Tropes:
* BerserkButton: Hurting Bart proves to be one for Strangles. Homer's routine strangling of Bart prompts the snake to strangle him MUCH worse in return.
* ABoyAndHisX: Initially, it starts with "A Boy and His Dog", but then it briefly goes with "A Boy and His Python".
* LoyalAnimalCompanion: Strangles' dialogue shows how loyal he became towards Bart.
* MyGodWhatHaveIDone: Santa's Little Helper feels bad after he bites Bart.
* NiceJobBreakingItHero: Strangles accidentally knocks down a set of chemicals that when mixed together create a toxic cloud that almost kills Bart when he stays in the school looking for Strangles.
* ReptilesAreAbhorrent: Averted. Despite his rather menacing appearance, Bart's pet snake Strangles is completely loyal to him. When Homer strangles Bart, Strangles strangles him, and when Bart is in danger thanks to mix chemicals in the school, he comes to rescue him. The worst thing he does is eat Martin's pet rabbit, which he did with Bart's approval.
* ShoutOut: The episode's title is a reference to ''Film/StopOrMyMomWillShoot''.