In Tropic Thunder, Robert Downey Jr. plays a white actor who undergoes surgery to play a black Vietnam-era Army sergeant. Downey perfectly satirizes the attention-getting narcissism of extreme movie transformations, a few of which we've listed here.
2 of 16 Universal/Everett Collection
Eric Stoltz, Mask (1985)To play Rocky Dennis, a boy born with the face-disfiguring disease lionitis, Stoltz spent three-and-a-half hours in makeup. He reportedly had to later reintroduce himself to cast members who hadn't seen him without his makeup on.
3 of 16 Paramount Pictures
Nicole Kidman, The Hours (2002)Donning a prosthetic nose to play reclusive author Virginia Woolf, Kidman was virtually unrecognizable in the role. Her acting, however, didn't go unnoticed, as Kidman earned the Best Actress Oscar for her performance.
4 of 16 Newmarket Films
Charlize Theron, Monster (2003)Taking a page out of Kidman's "ugly wins awards" playbook, Theron scrubbed off her makeup, popped in fake teeth and gained 30 pounds to play prostitute/serial killer Aileen Wuornos. And sure enough, she, too, won an Oscar.
5 of 16 Paramount Classics/Everett Collection
Christian Bale, The Machinist (2004)To play an eerily thin insomniac, Bale lost 60 pounds over four months by limiting himself to an apple and a cup of coffee a day. He reportedly wanted to lose another 20 pounds, but producers stopped him.
6 of 16 20thCentFox/Everett Collection
Gwyneth Paltrow, Shallow Hal (2001)Paltrow decked herself out in a fat suit for many of her scenes in this romantic comedy, which featured her as both Jack Black's obese object of desire as well as the thin version of her he sees in his mind's eye.
7 of 16 Warner Bros. Pictures
George Clooney, Syriana (2005)Though not as drastic as the 60 pounds gained by Robert DeNiro for Raging Bull, Clooney's extra 35 pounds were still startling. He got an Oscar, but it also caused an spinal injury that required surgery. That's dedication!
8 of 16 20th Century Fox/Everett Collection
Robin Williams, Mrs. Doubtfire (1993)Williams has rarely been afraid to do anything for comedy, including spending four-and-a-half hours in makeup each day to perfect the look of an elderly nanny.
9 of 16 Fox Searchlight Pictures
Hilary Swank, Boys Don't Cry (1999)To prepare for her Oscar-winning role as a transgendered teen boy, Swank lived as a man for a month, cutting her shoulder-length hair, taping down her chest with tension bandages and stuffing her pants with socks.
10 of 16 Dreamworks
Tom Hanks, Cast Away (2000)Production of the film was divided into two parts, separated by an an entire year in order to give Hanks time to lose 50 pounds and to grow a scruffy beard for the scenes that take place four years after being stranded.
11 of 16 Universal Pictures
Eddie Murphy, The Nutty Professor II (2000)Murphy's an innovator of movie transformations, playing multiple characters in several of his films. We just wish all of his attempts were a little more Coming to America, a little less Norbit.
12 of 16 The Weinstein Company
Cate Blanchett, I'm Not There (2007)Disappearing into roles is a Blanchett trademark. Of all the cross-dressing on this list, Blanchett's is the most natural. In addition to hair and makeup, she stuffed a sock down her pants to replicate a man's gait.
13 of 16 Walt Disney/Everett Collection
Bill Nighy, Pirates of the Caribbean (2006)So what if squid-faced Davy Jones was 99 percent CGI Nighy only needed his eyes and voice to bring the vivd animation to life.
14 of 16 Universal/Everett Collection
Sean Penn, Carlito's Way (1993)Penn shaved in a receding hairline and permed his locks to create Kleinfeld's greasy, frizzed-out do.
15 of 16 Columbia Pictures
The Wayans Brothers, White Chicks (2004)To become (disturbing) Hilton-like debutantes, the actor brothers required a seven-person makeup team. Ultimately, five hours of makeup each day and a combination of foam latex, body paint and wigs did the trick.
16 of 16 Warner Bros. Pictures
Hugo Weaving, V For Vendetta (2005)Weaving really stretched himself here. Between the bleached skin, long hair and constant smile oh, wait, never mind. That's just a mask.