The first season of Supernatural, an American dark fantasy television series created by Eric Kripke, premiered on September 13, 2005, and concluded on May 4, 2006, after 22 episodes.

[56] The series mythology further expands with the addition of the demon-killing Colt handgun near the season's end, lending to the "modern American Western" theme the producers were going for.

Everything that people know classically about vampires is wrong, so that just gave us an opportunity to plant our own flag and create our own creature.Although the weekly adversaries for the Winchesters were often based on urban legends, the writers tried to put their own spin on the stories for each of the episodes.

The figure is an escaped mental patient in the traditional myth, but the writers decided for the purposes of the show to make him the ghost of a hook-handed killer.

[60] Rather than focus on modern interpretations, Kripke and co-executive producer John Shiban decided that Supernatural's vampires would stem more from the original legends.

[61] Another element that would influence future episodes came about in "Hook Man" when writers Milbauer and Burton realized that shotguns shoot salt, a weakness for spirits.

Kripke deemed it the "perfect combination of occult element", as it brought together a "folkloric repellent of evil" with the "blue-collar aspect of shotguns".

"[64] Reapers were not in the original script of the episode, but were added later to give the writers a chance to create "scary" sequences and to explain the faith healer's ability.

[70] This addition pleased the writers of the penultimate episode "Salvation" because the Colt gave the brothers a way to fight Meg and also provided a reason for her to kill the Winchesters' friends.

Tucker felt that this opened "all this emotional stuff with the guys", as well as "brought back all the themes of the show and tied the season up into a nice big bow".

[72] Similarly, Kripke believed that the revelation of John being possessed by Azazel in "Devil's Trap" had to be, as it completed the two main storylines of the season—finding their father and tracking down the demon—at the same time, but had them find both characters in one body.

[75] For shapeshifting scenes in the episode "Skin", Kripke chose to base the transformation on that of An American Werewolf in London, using prosthetics and makeup rather than computer-generated imagery.

[76] The Ring's Samara influenced the titular villain in "Bloody Mary", though Kripke felt that she ended up looking too similar to the character due to her grisly appearance and the use of speed ramping to create a time-manipulation effect.

[78] Local sites often served as shooting locations, with much of "Dead in the Water" taking place at Buntzen Lake and the climax of "Wendigo" occurring in a Britannia Beach mine.

[87] An electric cello and woodwinds helped to create a big emotional tone in the episode "Home", with Lennertz feeling that the final cue "became a very cinematic musical moment".

[88] To fit in with the episode's ambiance in "Asylum", Gruska made the music very subtle; Lennertz felt that it was "creepy-crawly" like "a snake sneaking along the ground".

For example, music for the scenes involving the "professional" ghost hunters used percussion instruments to slightly mimic the Mission: Impossible theme.

For the pilot episode, Lennertz used a piano solo with discordant notes and reverberations to create a "really nasty"-sounding echo effect for the scenes involving Mary and Jessica's deaths at the hands of the demon Azazel.

[93] The episode "Dead in the Water" was the first to use what Kripke feels is the "Winchester emotion", which involves sorrowful and reverberating piano notes on top of strings.

[91] With Gruska writing Meg Masters' theme for "Scarecrow", Lennertz reused the music in "Shadow" but "took the scary up a notch" to imply to the viewers that she is both "more important and more devilish" than the other creatures in the episode.

[96] Among the many bands featured in the first season are AC/DC, Blue Öyster Cult, Creedence Clearwater Revival, Lynyrd Skynyrd, and Bad Company.

[77] Randy Shymkiw acted as special effects supervisor,[102] and the department found the episode "Asylum" to be quite a challenge because one scene has the vengeful spirit collapse into dust.

Because the character is pinned to the ceiling and burned to death, actress Samantha Smith was required to lie on a floor with two propane pipes spouting fire approximately five feet away from her on either side.

[102] In the episode "Bugs", the cast had to be sealed in a small area with hundreds of bees, and were stung despite wearing special costumes with cuffs sewn into their sleeves and pants.

[108] The actor portraying the vengeful spirit had to wear a wetsuit under his costume due to the extended period of time he was required to spend in the lake.

[110] For the episode "Shadow", rather than filming at the exterior location for the scene of Meg Masters being thrown out of a window to the street below, it was decided to not depict the impact, instead having the Winchesters look down at her body after the landing.

For the spirit's transition into Mary's normal form, Smith stood in front of a black background with wind blowing onto her, and the two scenes were later combined in post-production.

For the interior scenes used in the first moments of the Impala being hit, Jeffrey Dean Morgan, Padalecki, and Ackles were required to sit in the car, which was in front of a blue screen.

The intention was for a cannon to launch the Impala into the air at the collision point, causing the car to then barrel roll as the truck drives away.

The website's consensus reads, "Despite some too-hip dialogue and familiar thematic elements, Supernatural's vigilante brothers manage to stir up some legitimate scares.