It’s the oldest trick in the book — throw a little teaser in at the end of a movie that gets the audience excited for a sequel. Happens all the time. Hell, Marvel used those teasers (post-credits, to be fair) to build an entire billion-dollar shared movie universe. Unfortunately, not every movie studio is as successful as Marvel (and their new parent company, a little operation known as Disney). That means a lot of movies have teased sequels, only to never end up actually following through with a second film.

Here are 12 movies that seemed to promise another chapter of the story, only to leave fans wondering what happened next when no sequel ever showed up in theaters.

12. District 9

District 9 was a surprise sci-fi hit in 2009. Made for just $30 million by debut director Neil Blomkamp and executive producer Peter Jackson (Lord of the Rings), it was a found-footage film about a stranded alien race living in a government refugee camp in South Africa. When Wikus, the main character, accidently gets infected with strange alien DNA, he slowly begins to transform into one of them. After getting a first-hand dose of the discrimination the alien race suffers at the hands of humanity, he helps one alien escape back into space with his son when a cure for his transformation is promised.

The end of the movie shows a fully transformed alien version of Wikus leaving metal flowers for his still-very-human wife, as he awaits for his new friend to return with the promised cure. There have been plenty of talks about a potential sequel (or even a prequel), but it never seems to get pulled together. In 2010, it was “roughly two years away.” In 2013, Blomkamp insisted he still wants to make District 10. We’re still waiting.

11. The Fantastic Four (2015)

The first attempts at a Fantastic Four franchise didn’t too well. Rather than learn their lesson (or just sell the rights back to Marvel), Fox made the boneheaded decision to just reboot the whole thing with a new cast and new story. The movie was basically production hell, as constant arguments between the director, the writers, and the studio execs ended up producing a movie that could generously be called “craptastic.”

Despite bombing at the box office (and with critics), the movie teased a sequel at the end by having the foursome be awarded a new headquarters by the U.S. Military and adopting their official “Fantastic Four” moniker. They all agree to use their powers to help those in need, and seem ready for their next adventure. Until Fox pulled the plug on a planned sequel, which was originally scheduled to be released in 2017. There will probably be another Fantastic Four movie at some point in the eventual future, but only after the stink of the 2015 film wears off.

10. The Simpsons Movie

For a TV series that has been as successful as The Simpsons, it’s actually pretty surprising that they have only bothered to make a single feature film about the First Family of Springfield. Back in 2007, we were treated to The Simpsons Movie, a lazily-named flick about the family’s misadventures. It wasn’t groundbreaking cinema by any stretch of the imagination, but it was fun and made a bunch of cash — $527 million at the box office, compared to a much smaller budget of $75 million.

The movie ends with Maggie breaking the fourth wall by holding up a sign that says “Sequel?”, but so far Fox has done very little. Rumors have been trickling out over the past couple of years that they are trying harder to put the pieces together for another Simpsons movie, even pulling a planned 2015 episode from TV because they felt it was a prime candidate to be expanded into a full-length movie. Still though, nothing has been made official. As the series loses more and more steam after 28 seasons, it’s possible this sequel could get put on the back burner forever.

9. Freddy vs. Jason

Freddy vs. Jason was the long awaited showdown between two horror movie icons — the machete-wielding, unstoppable Jason Voorhees from Friday the 13th and the haunter of dreams Freddy Krueger from the Nightmare on Elm Street franchise. And honestly, it was pretty good. The movie does an excellent job of pandering to both fan bases, and even succeeds in turning Jason into a sympathetic character near the end. The movie ends with Jason emerging from Crystal Lake holding the decapitated head of Freddy. It seems like the battle is over, until Freddy’s head turns to the camera and gives a sly wink.

Since the movie was released in 2003, there was been plenty of things on the wishlist. Jason vs. Freddy 2, Jason vs. Freddy vs. Myers (featuring the villain from the Halloween series), and even Ash vs. Freddy. vs. Jason, bringing in Bruce Campbell to reprise his Evil Dead role. Instead, both series got original reboots, once again separating the horror icons back into different movie universes. The plans for a sequel are basically dead at this point.

8. Slither

Long before James Gunn was directing summer blockbusters like the Guardians of the Galaxy movies, he made his directorial debut with 2006’s Slither, a sci-fi comedy horror flick about an alien slug that begins to infect the population of a small town in South Carolina. Like most movies, the humans eventually save the day and destroy the alien parasite. Except for that post-credit scene where an innocent cat investigates the gory remains of a slug monster and becomes infected, opening the door for another Slither movie.

Unfortunately, the film was a box office bomb. It didn’t even make back it’s meager $15 million budget, although it was generally liked by critics and became a bit of a cult classic in recent years. Gunn did have plans for a sequel, but just couldn’t secure the funding needed, especially given the poor performance of the original. Maybe someone will let him do it now that he’s made $1.5 billion for Marvel/Disney by directing the adventures of Star-Lord and Rocket Raccoon.

7. RocknRolla

RocknRolla was a typical Guy Ritchie movie — hard-to-understand British gangsters do crime-related things and things go array. It’s very similar to his critically praised Lock, Stock and Two Smoking Barrels or Snatch. It had a great cast (including Gerrard Butler, Tom Hardy, Idris Elba, Mark Strong, Tom Wilkinson, Thandie Newtwon, among others) and actually ended not just with a subtle cliffhanger, but a full on title card that said “Johnny, Archy and the Wild Bunch will be back in The Real RocknRolla.

Ritchie claims that a script is already done and approved for a second movie, but he’s been kept busy with big projects like the Sherlock Holmes franchise and The Man From U.N.C.L.E. However, it’s been almost a decade since RocknRolla was first released, and the chances of Ritchie ever bothering to make a sequel keep getting slimmer and slimmer.

6. Green Lantern

In many ways, Green Lantern not having a sequel was a huge blessing. After all, if this DC Comics franchise had taken off the way the studio hoped, Ryan Reynolds would probably never ended up playing Deadpool. And that would be a damn shame, because he was so perfect in his role as the Merc with a Mouth. Although Reynolds might want you to forget about his first failed attempt at being a superhero, Green Lantern definitely did happen. It included a pretty good ending scene, too.

Following closely to the comic book origin story, Thaal Sinestro (Mark Strong) acts as Hal Jordan’s original mentor in the Lantern Corps. Together, they battle and defeat the villain Parallax, who consists entirely of the yellow element of fear. In a mid-credits scene, Sinestro is seen stealing the yellow ring. As Hal warned earlier, he instantly becomes corrupted by its power, turning into a power supervillain himself. The sequel would obviously pit the Green Lantern against Sinestro, but the sequel was never made. Unfortunately, the movie performed poorly with critics and the paying public. The planned sequel(s) were cancelled. But at least we got Deadpool! That movie was great!

5. Masters of the Universe

To capitalize on the incredible popularity of He-Man, a live action film titled Masters of the Universe was quickly thrown together in 1987 by Cannon Films. It starred Dolph Lundgren as the musclebound Prince Adam/He-Man, fresh off his breakthrough role as Ivan Drago in Rocky IV a couple years earlier. It also featured future Friends megastar Courtney Cox in one of her first film roles ever.

As you probably expect, the movie was terrible. It didn’t even make back it’s $22 million budget at the box office and was skewered by most critics for being a jumbled mess between kids comedy and an action/adventure, and not really succeeding at either. The failure of Masters of the Universe helped contribute to Cannon Films going out of business, and the post-credit scene with Skeletor emerging from the bottom of the pit and cackling “I’ll be back!” was basically ignored forever.

4. Flash Gordon

We can safely say that the only redeeming thing about the Flash Gordon movie was the all-Queen soundtrack. The rest of it was just… weird. Based on the comic strip with the same name, the 1980 sci-fi action film take the audience on a series of strange space adventures while Flash attempts to stop Ming the Merciless from destroying Earth. Naturally, the handsome blond quarterback of the New York Jet (yes, seriously) prevails over Ming and his Ring of Power. However, the final scene shows a mysterious gloved hand picking up the discarded ring as the words “The End… ?” display on the screen, with the evil laughter of Ming ringing out.

There was supposed to be a second movie, but multiple problems prevented it from being made. First of all, the original bombed at the box office. Secondly, star Sam J. Jones was mad that some of his dialogue had to be dubbed over by a soundalike actor. Tensions rose and the relationship between Jones and the producers deteriorated to unworkable levels. Any plans for a sequel were shelved forever.

3. Godzilla

In 1998, there was an attempt to reboot the Godzilla franchise for North American audiences. Naturally, that meant casting Matthew Broderick in a monster movie set in New York and marketed with new songs from the likes of Rage Against the Machine (“No Shelter”) and Puff Daddy (“Come With Me” feat. Jimmy Page). Just when you think the big green lizard has been killed off, the characters discover she had laid over 200 eggs inside Madison Square Garden.

The arena gets bombed and mama Godzilla makes a surprise return, furious about the death of offspring. After the U.S. Military finally succeed to taking down the legendary Japanese monster, the camera cuts back to MSG, where a single surviving egg hatches and a baby Godzilla lets out an adorable (but totally ferocious) roar.

The movie made a bunch of money, but was ravaged by critics for its bland acting and ridiculous plot. But most agreed the special effects were pretty good, so it wasn’t a total disaster. But that wasn’t enough to convince the studio (TriStar Pictures) to spend $150-$200 million to make a sequel, and the franchise remained dormant until 2014 — in North America, at least. Japan has their own separate Godzilla franchise.

2. Wanted

The Wanted movie was quite a bit different from the Wanted comic miniseries. In the comic, Wesley Gibson doesn’t inherit a job as a noble assassin. He inherits a role as an amoral supervillain. Yes, he’s actually a bad guy. In the movie, he’s the good guy, responsible for stopping the corrupt leader of the Fraternity, who has begun taking assassin-for-hire jobs.

By the end of the film, Wesley (James McAvoy) has been fully trained as an elite assassin and taken out the evil members of the Fraternity. He’s all ready to start his new life, even directly addressing the audience in the final scene. They began writing a sequel, but it was met with problem after problem. First, Angelina Jolie pulled out, forcing an entire script re-write. Then the key people involved got busy with other projects. The last word on a Wanted sequel was back in 2014, when McAvoy said he was still open to doing it, but that Universal seemed to be waiting on the exact right script, since the movie was so different than the source material.

1. Spaceballs

The parody film to end all parody films (although, it didn’t technically end parody films at all). Space Balls was a Mel Brooks directed sci-fi comedy, starring some legendary comics like John Candy and Rick Moranis. It was a hilarious knock at the Star Wars franchise, but also took subtle jabs at Star TrekAlien, and Planet of the Apes. It didn’t blow anyone away at the box office, but it’s become a memorable cult classic for comedy fans.

There have been multiple plans for a sequel, including Spaceballs 2: The Search for More Money (a title directly mentioned in the original flick) or even skipping right ahead to Spaceballs III: The Search for Spaceballs II. Unfortunately, it’s been a long time since 1987. Half of the original cast is dead, including Candy, Joan Rivers, Dick Van Patten, and Dom DeLuise. Moranis has all but retired from show business to take care of his family. Even Brooks is now in his 90s, and unlikely to bother with an entire movie shoot. Although now that Star Wars is Disney-owned and making new movies again, the time is perfect for a Spaceballs sequel.