Mary Winchester dies in the pilot episode of Supernatural when she interrupts the Yellow-Eyed Demon lurking beside Sam's crib. The demon kills her and pins her to the ceiling, then sets the nursery on fire.

Jared's favorite ice cream is chocolate chip cookie dough.

Azazel is the yellow-eyed demon, one of the Generals of Hell who planned to bring his army of black-eyed demons forth from Hell to unleash upon the world in preparation for the Apocalypse.

Misha Collins (Castiel) founded Random Acts, a non-profit organization aiming to conquer the world one random act of kindness at a time.

Before he moved to LA and became an actor, Jensen planned to study sports medicine at Texas Tech University and become a physical therapist.

Adam Milligan was the son of John Winchester and Kate Milligan, and half-brother to Sam and Dean.

Jared's middle name is Tristan

In "Changing Channels", Gabriel traps Sam and Dean in the TV show Dr. Sexy, M.D., and Dean guesses that Gabriel is disguised as Dr. Sexy because he's wearing the wrong shoes: "The thing that makes Dr. Sexy sexy is the fact that he wears cowboy boots. Not tennis shoes."

In November 2001, Misha Collins became the Guinness World Record Holder for organizing the world's largest international photo scavenger hunt: The Greatest International Scavenger Hunt the World Has Ever Seen.

The Ghostfacers was the name adopted by Harry Spengler and Ed Zeddmore for their reality TV series pilot about a group of paranormal investigators who cross paths with the Winchesters in several episodes. The Ghostfacers is run out of Ed's parents' garage.