The Simpsons, created by Matt Groening, is the longest running animated television series in the United States. It debuted in December 1989, and is still running. Its most well known characters are the members of the Simpsons family, parents Homer and Marge, and their three children, Bart, Lisa, and infant Maggie. Famously bizarre and dysfunctional, the family lives in an average, fictional city called Springfield with a cast of other odd characters.
The popularity of the Simpsons has allowed them to enter other mediums, including comic books and film. Simpsons catchphrases, like Homer’s “D’oh!” and Bart’s “Don’t have a cow, man!” have become omnipresent.
Sam: Same deal. Before that, there was Ogdenville. Before that, North Haverbrook and Brockway. Every fifteen to twenty years, it hits a new town.
John stays in the Sleep Easy Motel. This may be considered a reference to the Simpsons episode The Cartridge Family. In this episode, Marge and the children stay at the Sleep Eazy Motel, but the neon sign flickers, appearing to read Sle__ _azy Motel.
The name "Starla" for the blonde barfly (in Sam's version of events) is a possible reference to The Simpsons, which featured a trashy, bleached-blonde barfly of that name in the episode "A Milhouse Divided'. Her most famous line is, "Can I have the keys to the car, lover? I feel like changing wigs.".
The dinner theater and pepper steak coupon mentioned when Dean and Sam are talking to Gerard St. James is a likely shout out to the Simpsons episode, Mayored to the Mob, in which Mark Hamill, known for his role in Star Wars, stars in a local theater production of ‘’Guys and Dolls’’ and the dinner special is the pepper steak.
Bobby: So where's your brother?
Sam: Polling the electorate.
On The Simpsons, the local cops joke that Mayor "Diamond Joe" Quimby is "polling the electorate" whenever he meets an attractive young woman for a motel-room tryst.
The plot involving Lilith's possession of a little girl who "innocently" terrorizes her loved ones may be a reference to a 1961 episode of The Twilight Zone, "It's A Good Life", which was also parodied on The Simpson's "Treehouse of Horror II" .
Dean: Cram it with walnuts, ugly!
This is a line from Homer Simpson on The Simpsons.
The opening was very reminiscent of the opening of the Simpsons episode 'Mobile Homer' where Homer gets caught under the garage door (he's drinking beer in the garage - chases a spider, gets his head covered by spiders, then sprays bug spray in his face/eyes, trips on a skateboard and falls with his leg bent at an unnatural angle under the garage door. While trying to kill a spider by throwing a magazine at it, he accidentally hits the garage door control which triggers the door to come down on his throat several times.)
I.P. Freely is also one of Bart's favorite names for prank calling.