In a competitive industry like Hollywood, it's inevitable that directors and movie stars will clash at some point. Both jobs are typically associated with big egos and the merging of two individuals with inflated self-importance is like waiting for a ticking time bomb to go off.

Related: 10 Celebrities Who Were Once BFFS, But Are Now Enemies

In many instances, there is more drama behind the scenes than in the finished picture. Things aren't always rosy in the Hollywood Hills and the façade of glitz and glam can mask something far darker and pernicious. Sometimes actors interfere with directors' work; other times, directors take their craft too far. Clashing with the director can even cause actors to be fired, or, worse, blacklisted entirely from the industry. Colleagues don't always get along and there was no love lost between these directors and movie stars.

10 Judd Apatow And Katherine Heigl - 'Knocked Up'

Katherine Heigl Judd Apatow

Katherine Heigl has largely disappeared from Hollywood. There are various theories as to what caused this, but there is a persistent rumor that she is 'difficult' to work with. When filming Knocked Up, Heigl and director Judd Apatow clashed and she has claimed that 'no one had a good time' on set. Heigl later criticized both Apatow and the movie, branding it 'sexist'.

Related: 10 Hollywood Stars Labeled 'Difficult To Work With'

9 Stanley Kubrick And Shelley Duvall - 'The Shining'

Shelley Duvall in The Shining
via comicbook.com

Life was infamously made hell for Duvall on the set of The Shining. Kubrick kept picking on Duvall, demanding that she reshoot her scenes. The stress of filming grew so overwhelming that the actress's hair began falling out. Essentially, Kubrick terrorized Duvall into being a nervous wreck as a means of achieving maximum authenticity for her performance. He succeeded, but to the detriment of her mental health.

8 Lars Von Trier And Björk - 'Dancer In The Dark'

Bjork and Lars von Trier promoting Dancer in the Dark
via The Daily Beast

Possibly the most depressing musical ever made, Björk was so distressed during the filming of Dancer in the Dark that she allegedly ate her own cardigan. Von Trier is a notoriously difficult director to work with and loves to stir controversy (lest we forget the director proudly calling himself a Nazi at the 2011 Cannes Film Festival). The Icelandic songstress hated working with von Trier so much that she has said she will never act in a movie again. She has since alleged that a Danish director sexually harassed her, but has not explicitly stated who the individual in question is.

7 Billy Wilder And Marilyn Monroe - 'Some Like It Hot'

Marilyn Monroe in Some Like It Hot
via imdb.com

Some Like It Hot is a timeless classic that showcased the amazing talents of its three stars - Marilyn Monroe, Tony Curtis, and Jack Lemmon - all brilliantly unique in what they bring to this legendary comedy. But off screen, things were tense between Monroe and director Billy Wilder. The actress struggled to remember her lines, so Wilder had to write her dialogue on cards that she could read from during filming. Wilder went on to reference his troubled relationship with Monroe in The Apartment, released one year later. The movie features a sultry blonde character who is clearly a Marilyn Monroe parody.

6 Sydney Pollack And Dustin Hoffman - 'Tootsie'

Pollack and Hoffman in Tootsie
via Indie Wire

Tootsie remains a defining movie of the 80s. But director Sydney Pollack and lead actor Dustin Hoffman did not get along. Pollack felt that his expertise was being undermined by the film's star, who kept interfering with his creative process by suggesting that they add more risqué elements to the movie. Meanwhile, Pollack wanted to keep the movie family friendly. The director later called the experience a 'friendly war'.

5 David O. Russell And Lily Tomlin - 'I Heart Huckabees'

Lily Tomlin on David O. Russell
via Hollywood Reporter

Who can forget the leaked viral video of David O. Russell screaming at Lily Tomlin on the set of I Heart Huckabees? The video is difficult to watch: we are essentially watching a powerful man maliciously bully a highly gifted actress. According to insiders, that was not the first time Russell acted abusively towards actors. Years later, many stories surfaced detailing alleged maltreatment on set. Among the allegations were that he fought with George Clooney during the making of Three Kings, and that he humiliated Amy Adams when filming American Hustle.

4 Michael Bay And Megan Fox - Various Projects

Megan Fox and Michael Bay
via Newshub

Megan Fox caused controversy when she branded the Transformers director "Hitler." While Fox should not have conjured the fascist leader, Bay was undeniably inappropriate towards Fox. In addition to Bay supposedly being 'a nightmare to work for', he had previously cast Fox in sexualized scenes in Bad Boys II when she was just 15, though the actress has been adamant that he did not prey upon her. Regardless, we can only hope that the post-MeToo backlash will prevent this lewd behavior in future.

Related: A Timeline Of Megan Fox & Michael Bay's Rocky Working Relationship

3 Alfred Hitchcock And Tippi Hedren - 'The Birds'

Tippi Hedren and children in a scene from THE BIRDS, 1963.
via We Are The Movie Geeks

Biographer Donald Spoto penned a book called Spellbound by Beauty, detailing Tippi Hedren's mistreatment at the hands of Hitchcock when filming The Birds. This was dramatized in 2012's The Girl, with Sienna Miller as Hedren and Toby Jones as Hitchcock. According to Hedren, the venerated director relentlessly harassed her on set; when she rejected his advances, he ensured that true terror was instilled into the actress when filming the horror movie.

2 Stanley Kubrick And Marlon Brando - 'One-Eyed Jacks'

Stanley Kubrick and Marlon Brando
via Reddit

Another Kubrick entry, but this time it was the star of the movie who was in the wrong. Kubrick and Marlon Brando squabbled throughout the making of One-Eyed Jacks and Brando made life difficult for the acclaimed director. The pair clashed for 6 months, with Brando being his notoriously temperamental self. This eventually resulted in Kubrick leaving and Brando taking over as the movie's director.

1 Kevin Smith And Bruce Willis - 'Cop Out'

Kevin Smith and Bruce Willis filming Cop Out
via afternoonspecial.com

Smith has made no secret of the fact that he hated working with Bruce Willis on Cop Out. The two are certainly an odd pairing, with the indie director and Die Hard star failing to reconcile their differences. Smith called it a 'soul crushing' experience. However, in an appearance on Marc Maron's podcast, Smith praised the movie's other star, Tracy Morgan, and contrasted their positive working relationship to his unpleasant experience with Willis: "Everyone knows who it is. Put it this way, remember the really funny guy in the movie? It ain't him. He's a ****ing dream. Tracy Morgan, I would lay down in traffic for. Were it not for Tracy, I might've killed myself or someone else in the making of that movie."

Next: 10 Screen BFFs Who Can't Stand Each Other IRL