It's no secret that playing the bad guy can sometimes be more fun, and full of more creative options, than playing the good one. And in decades of filmmaking, the silver screen has seen hundreds of incredible, unnerving baddies steal the limelight, from Darth Vader to Anthony Hopkins's Hannibal Lecter. Indeed, certain actors have made playing on-screen villains with chilling perfection their signature, such as Christoph Waltz or Christopher Lee. However, there are also a number of stars, better known as the usually good-hearted leads, who've also explored their darker side. The latest protagonist-turned-antagonist is Emma Stone, the amiable star of <em>Crazy Stupid Love</em> and<em> La La Land</em>, who will transform into the evil Cruella de Vil in a live-action prequel to <em>101 Dalmatians. </em> Ahead of the film's 2021 release, we take a look at other beloved Hollywood stars who've transitioned to unexpected villains. He won a posthumous Oscar for his portrayal of the Joker, but the <em>10 Things I Hate About You </em>actor's casting was not met with widespread acclaim when it was first announced. The late Australian actor, who was mostly known for roles in teen-centric comedies (though he also had a wealth of meaty indie titles on his CV, too), was initially not deemed a good enough replacement for Jack Nicholson's Joker by critics. However, Ledger's truly disturbing performance is now regarded as one of his finest roles, by the Academy and fans alike. The bubbly actress, who starred in <em>Buffy the Vampire Slayer </em>and rom-coms such as <em>Simply Irresistible</em> (no, we don't remember it either), was known for her quick timing with roles as, typically, a high school pupil. And while she played a wealthy teen in this 1999 drama, Gellar was no innocent schoolgirl as the cunning Kathryn Merteuil, who schemed against her stepbrother Sebastian in a tale of love, jealousy and manipulation. His roles in <em>Jack</em>, <em>Mrs Doubtfire</em> and <em>Patch Adams</em> charmed a generation of children and adults alike, but Williams took a creepy turn in this 2002 psychological drama, his presence made all the more unsettling thanks to the actor's background as a family favourite. Williams played Seymour Parrish, a photo technician at a superstore who develops an obsession with a family whose pictures he has developed for years. The tremendous against-type performance was, arguably, one of Williams's greatest. <strong>Spoiler alert: </strong>The <em>Girls </em>star was chosen as the seemingly sweet Rose in Jordan Peele's 2017 horror precisely because of the connotations she brought to the role, the director previously stated. We won't completely spoil the ending, but suffice to say that Williams, who takes her African-American boyfriend home to meet her family in the acclaimed film, lull audiences into a false sense of security in a piece of mastermind casting. He's best known for his work as an action movie star, but Cruise's turn as a cold hit man in this 2004 thriller was a stark contrast to his work in, say, <em>Top Gun</em> or <em>Jerry Maguire</em>. The star both physically and emotionally transformed into the intense Vincent in what, in our humble opinion, is the performance of his career to date. A darling of America's box office and small screen, the <em>Friends </em>star switched from her usual romantic leads for a turn as the calculating dentist Dr Julia Harris in this 2011 comedy. Aniston plays a boss who harasses and attempts to blackmail her assistant, flexing her villainous chops with a hearty dose of black humour in this widely praised performance. The <em>Rain Man s</em>tar terrorised a generation of children as the mustachioed pirate, who kidnaps the children of a now-grown Peter Pan. While it's more of a comedy villain role, the punishments Hoffman inflicted on his crew (getting trapped in a box with live scorpions, anyone?) traumatised young viewers who'd previously known the actor as the loveable Tootsie. She was better known as a comedienne, but there was nothing funny about Mo'Nique's role as an abusive mother in this 2009 drama. The star played Mary, an unemployed woman who subjected her daughter, the titular Precious, to years of violence, cruelty and neglect in a heart-wrenching film that saw Mo'Nique take away an Oscar for Best Supporting Actress. The stalwart of stage and screen got her Hollywood break in this Stephen King adaptation, in which she played nurse Annie Wilkes, an obsessive fan who finds a famous novelist after his car crash. While Bates was relatively unknown in the film industry at the time, and therefore her casting itself wasn't that surprising, it's her discomfiting performance that warrants her inclusion in a list of most unexpected villains. You have no idea Wilkes is going to be quite disturbed as she turns out to be, thanks to Bates's nuanced portrayal. The funnyman was – and still is – known for his on-screen buffoonery, coming off the back of <em>Ace Ventura</em> and <em>Dumb and Dumber</em>, so he wasn't necessarily the obvious choice for the role of this DC baddie. And while Carrey's performance was typically flamboyant and OTT, there are some chilling moments that showed a side to the actor that audiences had previously not seen.