A sequel should build on the events of the original movie. There can be a few references to the original film to please fans, but overall, a sequel needs to be able to stand on its own. An example of a sequel that works is 22 Jump Street (2014) because it constantly makes fun of the fact that it's a sequel and that its plot is pretty much exactly the same as the original. Despite having an unoriginal plot, 22 Jump Street took the type of humor that made the first one great and applied it to the second, thus making it even funnier than the first. As a result, something better was created -- and that's what a sequel should be.

The films on this list are a whole lot worse than their originals. The movies on this list are the blatant cash grabs that every movie fan hates, the sequels that didn't need to be made, or sequels that had the original cast and crew but somehow became garbage. These terrible sequels should be studied by Hollywood as what not to do when making a sequel to a movie that people love. Not only are they turning new fans away from the original film, but they are damaging the reputation of the movie that came before it. These sequels were so bad that they defied all odds and managed to ruin the original movie.

Indiana Jones and the Kingdom of the Crystal Skull

Indiana Jones and the Kingdom of the Crystal Skull is the fourth film in the series, and many fans try to pretend that it doesn't exist. It was like any other Indiana Jones movie with a few moments of ridiculousness sprinkled in. For example, Indiana Jones survives a nuclear blast that launches him for miles by hiding in a refrigerator. Also, Shia LaBeouf plays a 1950's greaser, and it's hard to say which between that and the refrigerator stunt is more ridiculous.

What really made Indiana Jones fans despise this film, though, is the reveal at the end of the movie. Essentially, Indiana Jones is trying to solve the mystery behind this crystal skull thing that he acquires; he wants to know what it does and where it came from. Spoiler alert: it's part of an alien skeleton, inside of a hidden alien spaceship that rises out of the ground and flies away. Even for an Indiana Jones movie, the ending is a little unbelievable. Oh, and the movie implied that Shia LaBeouf was going to be the next Indiana Jones, and that made a lot of people very angry.

Spider-Man 3

Spider-Man (2002) started the Marvel universe hype train. This was the first superhero movie for a new generation of moviegoers who later became die-hard fans of Marvel. Tobey Maguire was a great Spider-Man throughout the trilogy, but his reputation was ruined by one scene in Spider-Man 3. In fact, as a terrible consequence, it's the only scene anyone remembers from all three films.

If you've seen Spider-Man 3, you know exactly what scene I'm talking about: the weird jazz scene with an emo Peter Parker. It's just awkward. Fans have tried to explain that the reason the scene is so awkward is because Peter Parker is acting in a way that he thinks is cool. And since he doesn't know what cool is, he comes off as unintentionally hilarious. That said, it's still a painfully awkward scene.

Even arguing that Spider-Man 3 was appropriately filled with teenage angst, the film simply tried to shove too many villains into the film. The film would have been fine with just Sand-Man and Harry Osborn as the Green Goblin, but shoehorning Venom (portrayed by completely the wrong guy) into the movie was too much. It was too overwhelming.

The Hangover: Part II

The Hangover: Part II was released two years after the first film, which should have been plenty of time to come up with an original plot. Instead of putting the characters in even crazier antics, the writers decided to pretty much copy the plot of the first film. For example, instead of losing a tooth and marrying a stripper (like in the first one), Stu gets a face tattoo and has sex with a transvestite. Doug is found right under the characters' noses (again) and Alan drugs his friends in both movies.

The Hangover would have gone down in film history as a comedy unlike anything before it. However, instead of preserving the legacy of the film, the movie studio decided it would be worth it to milk these characters for everything they could. As a result, by the time The Hangover Part III came out, everyone was just about tired of Alan, Phil, Stu, and Doug.

X-Men: The Last Stand

X-Men: The Last Stand (2006) was so bad that the film studio had to completely erase the movie from cinematic history in X-Men: Days of Future Past (2014). The X-Men movies made in the early 2000's were pretty enjoyable at the time they were released because there weren't many live action films made for fans of Marvel. However, it was the comic book fans, not the general audience, that hated X-Men: The Last Stand.

To start, the movie kills off Professor Xavier, Cyclops, and Pyro, plus the superpowers of Rogue and Mystique are removed. The film was made to be the final X-Men movie, which is why so many characters were killed off or had their stories laid to rest. Soon after, Hollywood realized that comic book movies were becoming fairly popular and that they could use Hugh Jackman as Wolverine to make a killing.

In X-Men: Days of Future Past, the characters go back in time (before X-Men [2000]) took place so that they could change the history in that cinematic world -- to keep characters like Charles Xavier, Cyclops, and Jean Grey alive.

Dumb & Dumber To

Dumb & Dumber (1994) is one of the stupidest comedies ever created, and because of that, it's hilarious. The jokes shouldn't be funny, but for some reason they are. And that's okay. It's one of those comedies from the 90's that everyone has seen and nobody hates despite the characters being frustratingly stupid.

Hollywood tried to revive Dumb & Dumber in 2003, with the prequel Dumb and Dumberer: When Harry Met Lloyd, and there was nothing redeeming about it. The film was a cash grab, again, with none of the original cast or crew working on it. When news broke that Jim Carrey and Jeff Daniels were working on Dumb and Dumber To, people were hopeful -- and then the first trailer came out.

Every funny joke from Dumb and Dumber To can be seen in the trailer -- and the trailer itself isn't funny. The jokes are predictable, poorly timed, and lack the touch that the first one had.

Speed 2: Cruise Control

Look, the original Speed (1994) starring Keanu Reeves and Sandra Bullock is one of the most ridiculous 90s action movies I've ever seen. Basically, a terrorist plants a bomb on a bus that will explode if the bus' speedometer drops below 50 mph. It's a cheesy action movie like The Fast & the Furious series that entertains you with its ridiculousness. The sequel, Speed 2: Cruise Control (1997) takes place on a cruise ship that has been hacked and sent at the normal speed a cruise ship moves but towards an oil tanker. To be honest, because the title of this sequel was so "punny," I really thought Speed 2: Cruise Control was going to be amazing.

Unfortunately, this is hands down the worst movie Sandra Bullock has ever been in (and she used to be in a lot of terrible movies). Seriously, Miss Congeniality really turned her career around. Speed 2: Cruise Control wasn't even so-bad-that-it's-good. In fact, it was nominated for eight Golden Raspberry Awards in 1997 and won for the category "Worst Remake or Sequel." Another notable contender in this category was Home Alone 3, which leads us to...

Zoolander 2

Zoolander 2 (2016) should be used as a lesson for Hollywood producers who think they can reboot a comedy and make a profit. The only redeeming quality of Zoolander 2 is that the marketing team had the genius idea to announce it by having Ben Stiller and Owen Wilson (as their characters) walk down a runway at Paris Fashion Week in 2015. Soon after, a trailer was released that revealed a little too much about the film.

The entire plot could pretty much be pieced together from the trailer. Punchlines and character reveals that could have been used as surprises in the movie were ruined by showing them in the trailer.

Zoolander 2 was made on a budget of $50 million and earned $56 million at the box office. It's a definite low point in Ben Stiller's career and one of those movies that you'll watch on Netflix while you fall asleep.

Home Alone 3/4/5

It's easy to understand how the studio messed up the Home Alone (1990-2012) franchise. After they filmed two, Macaulay Culkin was a little too old to play an adorable kid in Home Alone 3 (1997). Thus, Alex D. Linz was brought in as the new Home Alone kid, and Joe Pesci and Daniel Stern were replaced as the burglars. The movie actually turned a minor profit, but everyone thought it was a pretty poor film, and the franchise was thought to be dead.

However, in 2002, producers took another shot and released Home Alone 4 as a made-for-television Christmas movie. It sucked worse than Home Alone 3 and disappointed a nation. How hard can it be to make a decent film about a cute kid setting a bunch of traps that severely wound a couple of criminals?

In 2012, Home Alone: The Holiday Heist was released -- another made-for-television movie. Hopefully, it's the final Home Alone film. Box sets of all five movies are available to buy on Amazon, but who wants to say they paid for Home Alone. It's played on TV a hundred times every holiday season.

Son of the Mask

Son of the Mask (2005) should have never been made -- plain and simple. It was released 11 years after the original, and none of the original cast or crew took part in it. The star of the movie, Jamie Kennedy, now known for starring roles in terrible action films, tried to replace Jim Carrey. Kennedy should have known better that literally nobody could outshine or even match Carrey in a Mask film.

Part of the allure of The Mask was that nobody knew where The Mask came from. In Son of the Mask, writer Lance Khazei tried to explain the origin story of the mask. He was writing answers to questions that nobody was asking while creating the screenplay.

The Mask (1994) was loved because Jim Carrey was able to carry the film. In fact, the scenes with Carrey wearing The Mask are some of the most memorable moments from his career. It didn't need to be improved — and it didn't need anyone to try either. Furthermore, Hollywood needs to not reboot films a decade after the original came out.

S. Darko

S. Darko (2009) was a sequel that nobody wanted but somehow ended up getting made. The film, made eight years after the original, focuses on the life of Donnie's little sister, Samantha as she starts to have weird visions of her own. The only original cast member from Donnie Darko who appears in the sequel is the actress that played his little sister, Samantha. She was actually the least interesting character in the original, so it's a mystery why she was given a spinoff.

The movie was more than likely made to attract fans of the original, but it failed to do so. Pretty much everyone knew that this movie was going to suck before it was released. It was made on a budget of $4 million and made $4.9 million at the box office. Despite making a profit, the film was referred to by critics as a colossal failure at attempting to create a franchise.

In contrast, Donnie Darko was made on a budget of $4.5 million and earned $7.3 million at the box office. Furthermore, the movie was loved by critics and is considered one of the best independent films of all time.

Mean Girls 2

Mean Girls 2 is a made-for-TV movie that nobody cares about and most people haven't even heard of. Do you know how Disney releases direct-to-DVD films of their popular cartoons such as Mulan II, Cinderella II: Dreams Come True, and The Little Mermaid 2: Return to the Sea? This is kind of like that, but even worse.

What made Mean Girls a hit is that the screenplay was written by Tina Fey. She's the face of female comedians and never fails to write a punchline that will leave your belly aching. She also wrote 30 Rock and Unbreakable Kimmy Schmidt and is one of the best writers to have had a job at Saturday Night Live. The writers of Mean Girls 2 are known for hit films such as Barbie in the 12 Dancing Princesses, Cats Don't Dance, and Balto.

Mean Girls 2 is the farthest thing from being a sequel, while at the same time being a sequel. It's a film made specifically for little girls whereas Mean Girls was made for anyone to enjoy.

Book of Shadows: Blair Witch 2

The Blair Witch Project (1999) was a game-changer for horror movies. Without The Blair Witch Project, we wouldn't have any of the found-footage-style horror movies that we have today. It made Hollywood realize that with a budget as low as $60,000 they could make a found-footage horror movie that could make hundreds of millions at the box office.

What made The Blair Witch Project so horrifying is that it seemed so real. The actors in the film were listed as missing or deceased as part of a marketing campaign leading up to the film's release. The movie felt real, and that's what terrified people the most.

On the other hand, Book of Shadows: Blair Witch 2 failed to capture any sense of realism. Basically, the film revolves around a group of tourists that saw The Blair Witch Project and decide that they are going to see for themselves if the supernatural phenomenon shown in the movie is actually true. The audience wasn't as gullible the second time around, and the lack of realism in the sequel made people realize that the first film wasn't as factual as they thought that it was.

Grease 2

Grease (1978) is by no means a cinematic masterpiece. The film is a little tacky, the acting is cheesy, and the plot is a basic Romeo and Juliet spinoff. But there was just something about it that drew people to the movie. It was probably the soundtrack. People love to sing Summer Lovin' and Grease Lightning at karaoke bars.

On the other hand, Grease 2 (1982) is one of the worst sequels ever made. It tried to do the exact same thing that The Hangover: Part II tried to do: recreate a worse version of the original, hoping the audience will enjoy it as much. It's the same generic love story told about two lovers from completely different social groups without any of the catchy tunes to carry the movie.

You'll struggle to find anyone that has anything positive to say about Grease 2.

Shrek The Third

Shrek 2 (2004) should have been the final chapter in the Shrek saga. It was sort of everything that a sequel should be because it built on what the first film set up. You could argue that Shrek 2 is even better than Shrek (2001), but everyone can agree that Shrek the Third (2007) is trash. In fact, it's hard to tell what's worse -- the title or the actual movie.

The interesting thing about Shrek 2 is that Shrek was forced to adapt his ogre lifestyle to the lifestyle of Fiona's parents. Watching Shrek struggle with basic manners was funny for a few minutes, but Shrek the Third tried to drag that out for an entire movie.

After its release, people gave up on the Shrek franchise. Dreamworks was milking the characters by launching too many spinoffs, short films, television series, and television specials. The spinoffs were made for children, but Shrek was made for anyone to enjoy. There are a number of sex jokes hidden throughout Shrek and Shrek 2 that children wouldn't understand. You even literally see Lord Farquaad's boner in one of the scenes.

Shrek the Third killed the franchise for a lot of fans, which is a shame because Shrek Forever After (2010) isn't so bad.

Anchorman 2: The Legend Continues

It takes a certain type of person to find Will Ferrell funny. He's released a number of hilarious comedies over the years -- but perhaps his most quotable is Anchorman: The Legend of Ron Burgundy. When Anchorman 2: The Legend Continues was announced and highly promoted, it looked promising. The movie was going to feature the original cast, producer, director, and writers. It was set up to be a smash success, proving that sequels to comedy movies can actually be good. And then it came out -- and nobody can remember a thing about it.

The most memorable thing about the movie is that the plot makes no sense. At the start of the film, the viewer is led down a promising plot where Ron Burgundy creates the first 24-hour news channel and provides the first ever news coverage for a police chase. But, instead of sticking to that great story line, about an hour or so later, Ron ends up with a pet dolphin and is living in the middle of nowhere. It's nonsensical in the worst way possible, and fans were left disappointed. Again. But, at least the movie studio made a ton of money. Right?

Sources: Wikipedia; IMDB