When director Sam Raimi released the original The Evil Dead in 1981, Stephen King dubbed it “the most ferociously original horror film of the year.” The splatter flick about a small group of friends enduring the consequences of selecting a demon-infested cabin for a weekend getaway spawned two sequels, a 2013 reboot, and a current television series, Ash vs. Evil Dead.

None of that may have happened if Raimi hadn't first elected to shoot Within the Woods, his 1978 prototype short that helped convince investors he could make an effective horror film. And while The Evil Dead may be one of the best-known examples of a genre filmmaker offering a proof-of-concept project, it’s far from the only one. Check out eight other horror features that started life as short scares.

1. MONSTER (2005) // THE BABADOOK (2014)

It took director Jennifer Kent nearly a decade to turn her 10-minute short, Monster, into a feature, but the wait paid off: The Babadook received some of the best critical notices of any film in 2014. In both the short and full-length story, a single mother and her child confront a monster in their home that turns out to be as much a metaphysical threat as a real one. Kent said she expanded the short as a result of financial constraints: financiers in her native Australia found other scripts for her first feature film too ambitious, leading her to return to the more intimate (and less expensive) narrative. Kent calls the original a “baby Babadook.”

2. OCULUS: CHAPTER 3 - THE MAN WITH THE PLAN (2006) // OCULUS (2013)

Mike Flanagan’s logline was simple: throw a guy into a room with a haunted mirror and see what happens. Oculus: Chapter 3 - The Man With the Plan, a 29-minute short, was the result. (There was no chapter one or two.) Flanagan got plenty of offers from Hollywood following its release—but few wanted to entrust him to direct a feature. After using Kickstarter to fund the small independent movie Absentia, Flanagan was able to expand the mirror idea for Oculus, a film starring Karen Gillan (Doctor Who) that opened up the narrative to include more than one time period.

There was just one additional wrinkle: Flanagan didn’t want to do it as a found footage film, which studios kept insisting upon. After negotiations, he got his wish: Oculus found a receptive audience without the gimmick.

3. GRACE (2006) // GRACE (2009)

It’s rare that a 6-minute short bears more recognizable performers than the eventual feature film, but director Paul Solet’s Grace is an exception. Shot on a microscopic budget in 2006, Solet was able to convince Beverly Hills, 90210 star Brian Austin Green to participate. The short—about a mother experiencing a very unconventional and very alarming pregnancy—was filmed strictly as a calling card, as Solet had written a full-length script prior but had problems getting interest. After touring the festival circuit, he managed to obtain funding from ArieScope Pictures for a film. Although it’s not known what effect watching the short has had on viewers, at least two men passed out during the feature’s premiere.

4. IN A CORNER (1998) // JU-ON: THE GRUDGE (2002) // THE GRUDGE (2004)

Japanese horror has been fertile source material for plenty of Hollywood remakes, but there are still a number of fans who prefer the originals. In the case of Ju-On, director Takashi Shimizu’s tale of a family pursued by accursed entities, the English version was actually the third to be filmed. In 1998, Shimizu shot two brief projects on videotape for the Japanese horror TV series Haunted School G that contained several of the core concepts found in the features, including the infamous “crawl” of leading creepy girl Kayako.

5. TOOTH FAIRY (2001) // DARKNESS FALLS (2003)

Comic book writer Joe Harris’s short film, Tooth Fairy, had an irresistible hook for film studios: a malevolent tooth fairy that hunts children. After the film made festival rounds, Revolution Studios purchased the rights for a full feature adaptation. Harris said in 2010 that he wrote several drafts of the film before a “heavily rewritten” version made it into theaters.

6. THE SITTER (1977) // WHEN A STRANGER CALLS (1979)

When a Stranger Calls may not hold up for its entire running time, but most who have seen it will tell you that its opening 10 minutes (above) might be among the scariest committed to film. The sequence—which features Carol Kane getting some disturbing calls from a mysterious voyeur while babysitting—was largely mapped out in director Fred Walton’s short film, The Sitter, which was made for $12,000. While the feature drew criticism for not having enough plot to sustain itself past those early moments, they’re worth the price of admission. In 2006, Simon West directed a remake of the feature version.

7. LIGHTS OUT (2013) // LIGHTS OUT (2016)

How short can a film be and still attract interest from major studios? Maybe as short as three minutes, the approximate running time of director David Sandberg’s Lights Out, a 2013 film that consisted of nothing more than a woman being terrified by something in the dark. It was enough for producer and filmmaker James Wan (The Conjuring) to sign Sandberg for a full-length version. In addition to that pivotal opportunity, Wan is also positioning Sandberg to direct the sequel to the killer-doll film Annabelle. Not bad for a film barely longer than a commercial break.

8. SEASON’S GREETINGS (1996) // TRICK ‘R TREAT (2007)

Likely one of the few senior thesis projects to inspire a feature, Michael Dougherty’s animated short from 1996 preceded his horror anthology from 2007. In both the college and feature films, the ominous trick-or-treater, Sam, is front and center. Dougherty reportedly cut his hand while hand-drawing the animation, with the blood specks making it into the finished edit.