Strangles is the python bought by Bart after Santa's Little Helper joined the police force.
Strangles was Santa's Little Helper's replacement. Bart took his snake to show and tell at school where he escaped. Strangles knocked over some ethanol and nitrous oxide at the schools lab, creating a toxic cloud. Bart runs back into the building to save Strangles, with Santa's Little Helper running in after Bart. Bart collapsed inside the building and both Strangles and Santa's Little Helper tries to rescue him. Bart chose Santa's Little Helper to save him. Strangles got adopted by Groundskeeper Willie after that, who kept him as a pet in the school's fire hose cabinet.