None of the cast or crew members ever expected for show to last as long as it has. Misha Collins (Castiel) has stated that at the 100th episode party, someone said "Maybe we'll see you at the 200th!" and everyone laughed at the idea, thinking the show would be long gone by that time. The party for the 200th episode of the series took place in October 2014.
Originally Jensen Ackles auditioned for the role of Sam Winchester. When Jared Padalecki came in and read for Sam a slight recasting was done. Producers called Jensen and asked if he'd rather use his charm for Dean, saying he was the Han Solo character of the duo and what kid didn't grow up wanting to be Han Solo? Jensen accepted. It became known that he was previously interested in that role, because Dean was funny.
Jared Padalecki (Sam Winchester) dislocated his shoulder while wrestling with Osric Chau (Kevin Tran). The writers were then forced to make up a story as to why Sam was wearing a sling in the beginning of Season 10.
Riverview Hospital, a large mental health facility used as the main set in the season 1 episode Asylum, has also substituted for a prison, a regular hospital, and an apartment building on different episodes of the show. This is evidenced by seeing the same distinctive staircase in different episodes.
An important aspect of the show's music is classic rock, most of which comes from creator Eric Kripke's own record collection, although one of his favorite bands - Led Zeppelin - has always been too expensive to license.
Every single season finale begins with a recap montage of the key moments of the season, to the tune of "Carry On Wayward Son." The exception was season 1 when the song is heard in penultimate episode of the season. Season 11 finale does not use this song either.
With the CW's announcement that Supernatural was renewed for an 12th season. It will break the record for 2nd longest running consecutive Sci-Fi series. Smallville (which also stars Jensen Ackles) held the record previous. It is currently held by BBC's Doctor Who.
While it may be coincidental the choice of the name Winchester for the family is interesting. There is a rather famous mansion in California built by Sarah Winchester, wife of the gun magnate, which was under constant construction for 38 years for paranormal reasons. According to legend the reason for the constant building was a medium telling Mrs. Winchester that if she ever stopped building the spirits of those killed by Winchester rifles would come after her. The strange design of the mansion is also attributed to this. It was built with dead ends and stairs to nowhere allegedly to confuse spirits.
Misha Collins (Castiel) was originally only supposed to make a couple of guest appearances in season four, but due to enormous fan response, he has been a regular on the show ever since. Collins has joked that he maybe wouldn't have used such a low gravelly voice for his role had he known he'd be on the show so frequently because it hurts his throat.
Many episodes are either named after movies ("Children Shouldn't Play with Dead Things", "The Usual Suspects", "I Know What You Did Last Summer") or classic rock songs ("In My Time of Dying", "Born Under a Bad Sign", "What is and What Should Never Be", "Sympathy For The Devil", "When The Levee Breaks").
The car Sam and Dean drive is a 1967 Chevrolet Impala four-door sedan, which used to be known as the Metallicar by fans of the show. The show uses five black Impalas. Dean has nicknamed the car "Baby", as it is also known by fans today.
Many of the episodes are based on existing legends, myths, and ghost stories. For example the episode "Crossroads" is based in part on the legend of Robert Johnson - who in turn borrowed it from another Blues singer.
Both Jared Padalecki and Jensen Ackles auditioned for the role of Superman/Clark Kent in some form. Padalecki was a finalist for director McG's reboot while Ackles was the second choice to play a young Clark Kent in the show Smallville (2001). Jensen was later cast as Jason Teague in Season 4.
In season 2, Linda Blair guest stars as a detective investigating the brothers. At the end of the episode, she says, "I need you two out there doing what you do best. I know I'll sleep better at night." This is clearly a nod to her role as Regan in The Exorcist, as she was possessed by a demon. As the brothers walk away, Dean says, "Does she look familiar to you?" Then he exclaims that he is craving pea soup, which was what Linda Blair 'projectile vomited' in The Exorcist.
Dean's car, up until episode 2.20, had Kansas (the brother's origin state) plates with the number KAZ 2Y5. It currently now has Ohio (Supernatural's creator Eric Kripke's home state) plates with a Franklin county sticker (25) and the number CNK 80Q3. The plates are changed again in later seasons to Oregon plates SMD 5B2, as seen in episode 13 of season 7.
The Supernatural fan base is repeatedly referenced throughout the show and even makes a few special appearances, including the 200th episode. This was made possible through the character Chuck Shurley and his prophetic book series about the Winchesters.
In season 2, episode 12, Night Shifter, the magazine that Ron shows Sam and Dean (disguised as FBI agents) has a picture of a humanoid metal robot, or "Mandroid" as Ron insists on calling it, with the caption "Cyberman". Both the name "cyberman" and the likeness of the robot are references to Doctor Who, with the cybermen being prominent antagonists in the show.
Whenever the brothers are introduced (by their real names) by themselves or others they are almost always referred to as Sam and Dean rather than Dean and Sam. This is a nod to Jared Padalecki's name being displayed first in the opening credits. Only in episode 1.8 do they refer themselves as Dean and Sam.
Eric Kripke is a big fan of Classic Rock, and thus wanted it to be played on the show. He wrote in the pages of the pilot script "CUE MUSIC And you can take your anemic alternative pop and shove it up your ass. Dean plays bass thumping, pile driving Zeppelin, and he plays it loud."
The character of Bobby Singer was originally supposed to be named Bobby Manners, after Robert Singer and Kim Manners, who had both greatly contributed to the show. However, after discovering that there was an actual Bobby Manners, the character's last name was changed to Singer.
Sebastian Roché (Balthazar), Misha Collins (Castiel), Kurt Fuller (Zachariah) and Mark Sheppard (Crowley) all appeared in the TV series "Charmed." Roché and Sheppard both played demonic characters, while Fuller and Collins played characters in need of help.
In season 1 Sam and Dean posing as FBI agents use the alias's 'Agent Ford' and 'Agent Hamill' this is a reference to Harrison Ford and Mark Hamill the two main characters in Star Wars which star Jensen Ackles (Dean) loves very much.
In episode 18 of season 2, called "Hollywood Babylon" while walking to stage 9 Dean mentions wanting to take time off and go swimming, to which Sam responds "This seem like swimming pool weather to you Dean? It's practically Canadian." This is a nod to the actual filming locations in the show, which are all in Canada. Also, a play at Jared playing a love interest on Gilmore Girls.
This is the second time Jensen Ackles plays a sibling to a character named Sami/Sammy as he previously appeared on the daytime soap "Days of Our Lives" as Eric, twin brother to Alison Sweeney's Samantha Brady. Sweeney's character usually went by the name Sami. Ackles' character tends to call his brother Sam, "Sammy" on Supernatural.
Jeffery Dean Morgan, Jared Padalecki, and Jensen Ackles have all been associated with the name Dean. Jared Padalecki's character in Gilmore Girls was named Dean, Jensen Ackles' character on Supernatural is named Dean, and Jeffery Dean Morgan has Dean for a middle name.
In a season 2 episode, Amber Benson plays a "vegetarian" vampire Lenore who refuses to feed on humans. Amber is best known for her character Tara, a witch who is friends with and helps Buffy the Vampire Slayer.
Misha Collins has created something on Tumblr called "Mishapocalypse" where on April 1st, everyone in the supernatural fandom does the following: Posts pictures of Misha, changes their profile picture to Misha's serial killer face, refers to each other as Misha, and trick other fandoms
Cast members Jensen Ackles and Jeffrey Dean Morgan both have had connections to the characters of Batman and Superman. Ackles had a voice role in "Batman: Under the Red Hood" as well as a supporting in the 4th season of "Smallville". Jeffrey Dean Morgan had a cameo role as Thomas Wayne in "Batman v Superman: Dawn of Justice".
Both Jared Padalecki and Jensen Ackles did remakes of classic horror movies that were released in the year of 2009. Jared starred in Friday the 13th with actress Danielle Panabaker and Jensen starred in My Bloody Valentine in 3D with actress Jaime King, In which all of them have and still are working on tv shows on the CW. Jensen Ackles and Jared Padalecki on Supernatural, Jaime King on Hart of Dixie and Danielle Panabaker on The Flash.
The trivia items below may give away important plot points.
Early on in the series, Dean's cell number is given, and for a while the studio had it set up so that anyone dialing the number would hear Jensen Ackles reading the message: "This is Dean Winchester. If this is an emergency, leave a message. If you are calling about 11-2-83, page me with your coordinates." The number is 1-866-907-3235. This number now leads to a fax machine, but it is not known where that fax machine ends up.11-2-83 is Sam and Dean's mother Mary Winchester's death date.
Producers considered several methods of motivating Sam to take to the road with Dean. Turning Jessica evil was an option briefly, but in taking a page from Star Wars it was decided that her death would be the ultimate motivation for leaving home.
The character Sam was sick for a large part of Season 8 due to the Demon Trials, and actor Jared Padalecki's performance was so convincing that a portion of fans became concerned about him, worrying that he was actually sick.
Genevieve Cortese' was cast as the character Ruby for the fourth season (replacing Katie Cassidy), and her character eventually becomes romantically involved with Sam (Jared Padalecki). In their real lives, Cortese and Padalecki also became romantically involved, and after they married in 2010, she changed her last name to "Padalecki" both personally and professionally.
Several references throughout his appearances on the series point toward the character Rufus Turner (played by Steven Williams) being Jewish. He makes jokes about Hanukkah and keeping kosher, and most significantly, when he dies, the Winchester brothers and Bobby give him a funeral in a Jewish cemetery and discuss his level of Jewish ritual observance (or lack thereof). Although the funerals for previous hunters had included a ceremonial funeral pyre, the show makes a point of showing that Rufus gets buried without cremation (since cremation is against Jewish tradition).
Jared Padalecki has played the greatest number of characters for an individual actor. He not only plays Sam Winchester, but he also played Lucifer, Gadreel, Leviathan Sam, Souless Sam, Shapeshifter Sam, Himself, and briefly Meg. Oddly enough, Jensen Ackles, his onscreen brother, has played the fewest characters, playing only Dean Winchester, Leviathan Dean, Shapeshifter Dean, and Himself. In a later season he also played Demon Dean when the mark of Cain changed him.
Dean's primary sidearm is a Colt Series 70 1911, with a nickel finish, full engraving, and ivory grips, chambered in .45acp. Sam carries a Taurus PT92 with a stainless steel finish, mother of pearl grips, and chambered in 9mm. The only exception is season six when Sam loses his soul. "Soulless Sam" carries an HK USP Expert chambered in 9mm. Once Sam regains his soul, he switches back to the Taurus PT92.
In the show, Chuck, AKA God, uses a pen name to write the Supernatural books: Carver Edlund. The producer's name is Ben Edlund and the co-producer's name is Jeremy Carver. Putting the last names together results with Chuck's pen name.
In The Girl Next Door episode there's the scene where a leviathan is checking over a credit card statement and asks about "Mistress Magda", before hanging up on the customer, because of getting a trace on Dean and Sam. Mistress Magda is the name Chuck says when he answers the phone in Swan Song when Dean calls for the location of the fight between Michael and the Devil, the thought to be last time we see Chuck and he mysteriously disappears in a puff of white smoke.
The biblical Burning Bush Sam sees at the beginning of Season 11, Episode 9, "Oh Brother, Where Art Thou?", is a popular ornamental shrub in the Euonymus genus, Euonymus alatus, commonly known for its fiery autumn foliage as "Burning Bush".
John and Mary are a reference to the family Jesus from the New Testament. John Winchester baptizes Dean and Sam into the life of hunting monsters, and Mary gives birth to the two men that will decide the fate of the world. As can be seen in the progression of the series, many of the demons, ghosts, and enemies of Sam and Dean are based on legends and stories from different cultures. The series in particular has a biblical storyline, and as depicted by the names of the Winchester's parents, the brothers were born to live and fight during the apocalypse as the saviors of the world and mankind. Although the series itself was not specifically designed to offend anyone, there is an underlying story line of angels and demons and their fight for earth in the end times, and to show how things can be divided.
In season five on the episode "fallen idols" Paris Hilton is a guest star. In the end of that episode Dean says: "I've never even seen house of wax". House of wax is a horror movie starring both Paris Hilton and Jared Padalecki.
In Season 4 Episode 17 'A terrible life'. Dean and Sam are both put into an alternative life by an Angel, they don't know who each other are and they are called Dean Smith and Sam Wesson. Clearly a reference to the famous weapons company Smith and Wesson.