Stars’ Stunning On-Screen Transformations (PHOTOS)

It isn’t easy being ridiculously good-looking. In order to be taken seriously in their big screen roles, many of Hollywood’s genetically-gifted stars have been forced to alter their perfect bodies by gaining massive amounts of weight, losing massive amounts of weight, or just plain uglying up.

Just this week, Black Swan stars Natalie Portman and Mila Kunis copped to dropping tons of weight to play ballerinas. Soon after, Michelle Williams revealed she packed on about 15 for the romantic drama Blue Valentine.

Click through for Celebuzz’s comprehensive look at stars’ most drastic on-screen transformations and tell us in the comments – who’s metamorphosis was most dramatic? Continue the discussion over at the Celebuzz Facebook page.