Sean Penn, “Carlito’s Way”

Sean Penn, “Carlito’s Way” (1993)
While we’re kind of used to Sean Penn the Serious Thespian by now, at the time of Brian De Palma’s “Carlito’s Way,” he was barely out of his leading man/heartthrob phase, which made his appearance here all the more surprising. That’s if you recognized him at all. Coaxed out of an alleged early retirement to play the role, Penn went all-in, shaving back his hairline and perming the remainder which, in combination with the character’s glasses and '70s wardrobe, made the lawyer Kleinfeld look and feel completely different from anything he’d played before. But not different enough from everybody—lawyer Alan Dershowitz threatened a lawsuit at one point as he claimed the portrayal was defamation.

Russell Crowe, “The Insider”

Russell Crowe, “The Insider” (1999)
Russell Crowe had been on the scene for quite a while before 1997’s “LA Confidential” gave him his breakout and also defined his hard-edged, physically strong, masculine persona. And so to see him, just two years later, play much older, fatter and more downtrodden than we’d imagined possible, was a real surprise. But for his turn in Michael Mann’s excellent based-in-truth story of a tobacco lobby whistleblower, Crowe not only gained 35 pounds, he shaved back his hairline, repeatedly bleached his hair, and had liverspots and wrinkles applied daily to age him by 20 years. He got an Oscar nod for his pains, and bounced back to full health and then some the following year for “Gladiator.” Crowe schlubbed up again, gaining 63 pounds for his role in Ridley Scott’s “Body of Lies” in 2008, but to lesser effect in what turned out to be a rather lackluster film.

Tom Hanks, “Philadelphia”

Tom Hanks, “Philadelphia” (1993)
So we’re going with Tom Hanks’ Oscar-winning turn as a crusading gay AIDS patient in Jonathan Demme’s “Philadelphia” just because again, like Sean Penn, this was really one of the first times we’d seen Hanks deviate from his cute, boyish romantic lead roles (“Sleepless in Seattle” released the same year). And after he’d lost 35 pounds and shaved his head, to say nothing of the make-up and physical frailty he worked into his performance, his appearance was a revelation. Of course, he arguably went even further for 2000’s “Cast Away” for which he gained 50 pounds to play the newly-stranded FedEx employee, only to have to work to lose all of that and more (as well as growing a wild beard and long hair) during a filming hiatus, so that he could accurately portray the same man after years of isolation and privation.

Matt Damon, “Courage Under Fire”

Matt Damon, “Courage Under Fire” (1996)
The year before Matt Damon’s annus mirabilis of 1997, when “Good Will Hunting,” “Chasing Amy” and “The Rainmaker” were all released, he appeared in a small role in Ed Zwick’s Denzel Washington/Meg Ryan-starrer, “Courage Under Fire.” For only two days of filming as an opiate-addicted soldier, Damon lost 40 pounds in 100 days, apparently afterwards having to take a long course of medication to combat issues this had created with his adrenal gland. In 2009 however, he got to do the reverse, and packed 30 pounds onto his ‘Bourne’-lean body for Steven Soderbergh’s “The Informant!

Mariah Carey, “Precious”

Mariah Carey, “Precious” (2009)
Well, it’s perhaps more a mark of how we expect Mariah Carey to look in real life (though how much music videos, red carpet appearances and judging “American Idol” can be considered real life is debatable), that the dowdy bangs and under-made-up face she sports in Lee Daniels’ “Precious” were such an eye-opener. But in her role as a tough-talking social worker (allegedly originally to be played by Helen Mirren which, well, how often do we get to link those two names?), Carey is not only impressively unglamorous in appearance, but she also, in marked contrast to the breathy girlishness we might associate with the gazillionairess, sounds like she’s been gargling nails for a week. And to think this is the cover art for her next single...

A few others that just missed the cut: Renee Zellweger's yoyoing weight for "Bridget Jones's Diary" and its sequel has been much remarked upon, however we'd argue that she hardly looks unlike herself even with the extra pounds so, transformation maybe not so much. Nicole Kidman did the dowdying down thing for "The Hours" that yielded her an Oscar, but aside from the slightly unconvincing nose we didn't find it totally transformative. Matthew Fox threw his all into of all things, "Alex Cross," emerging impressively ripped as the villain in that film, but it was kind of an arc from buff to buff-er so we excluded it. Also excluded were heavy prosthetic jobs like Eric Stoltz in "Mask" and John Hurt in "The Elephant Man."

Natalie Portman and Mila Kunis both underwent rigorous training and experienced significant weight loss for their roles in "Black Swan," but neither were exactly obese to begin with, so the sculpting hardly rendered them unrecognizable. Sylvester Stallone schlubbed down for the underrated "Cop Land" to good effect, as did George Clooney for "Syriana" and Joaquin Phoenix for extended prank "I'm Still Here," but again, not quite to the point of double-taking their identities.

Anne Hathaway lost a lot of weight and chopped off her locks to play Fantine in "Les Miserables"and got a Supporting Actress Oscar for it, but that somehow made her look more like herself than ever. And to close on a beefcakey note, Jonah Hill and Chris Pratt both shed pounds recently for "21 Jump Street" and "Zero Dark Thirty," respectively and looked good. Pratt, in fact has gone even further for the upcoming "Guardians of the Galaxy" so no doubt his abs will be providing us with one (or six) more reasons to check that out. Also upcoming is David O. Russell's "American Hustle," which features more crazy wigs and odd facial hair than we can shake a stick at. Tell us your favorites below.