Actors have to to change their image for almost every role they play, even when it's a similar role to one they've played before. We've all had moments when the credits roll and you cannot believe that an actor changed so drastically you didn't even realize they were in the movie (this was exactly my reaction to numbers 13 and 4 on this list)! Some actors, such as Tilda Swinton, have a gift for being transformed while others can look completely different with a change of makeup. While I cannot exhaust every amazing transformation done for the silver screen, I will share with you the most shocking or impressive transformations I have seen.

15. Christian Bale as Trevor Reznick, "The Machinist"

Still recognizable, but the weight loss is terrifying.

14. Margot Robbie as Tonya Harding, "I, Tonya"

Apparently, Margot Robbie had no idea Tonya Harding was a real person when she got the role, but she definitely got into character with her '80s hair and weight gain.

13. Tilda Swinton as Dianna, "Trainwreck"

I had no idea she played this character until months after I watched this movie.

12. Charlize Theron as Aileen Wuornos, "Monster"

Charlize Theron nailed the serial killer's frown and her weathered appearance to the point where you almost forget how stunning she can be.

11. Ewan McGregor as Ray (and Emmett) Stussy, "Fargo" (TV series)

Not only does Ewan McGregor undergo a transformation for the TV adaption of Fargo, he also plays both Stussy brothers (who also happen to look very different).

10. Ross Lynch as Jeffrey Dahmer, "My Friend Dahmer"

Something about a Disney star playing young Jeffrey Dahmer, the infamous cannibal and serial killer, is incredibly unsettling.

9. Nicole Kidman as Virginia Woolf, "The Hours"

Prosthetic nose + hair dye = new person.

8. Karen Gillan as Nebula, "Guardians of the Galaxy" series

Our favorite Doctor Who companion resembled a demonic cyborg with her black contact lenses and full-body paint to look colorful and mechanical.

7. Ralph Finnes as Voldemort, "Harry Potter" series

Instead of the usual addition of features, they removed most of Ralph's to make him the evil wizard from the beloved books.

6. Rooney Mara as Lisbeth Salander, "The Girl With The Dragon Tattoo"

Mara actually pierced her nose, eyebrows, lip and ears for this role. She also bleached her eyebrows and committed to Lisbeth's edgy 'do.

5. Marion Cotillard as Edith Piaf, "La Vie En Rose"

Marion ages quite horribly in the French biopic about the troubled Edith Piaf. Normally gorgeous, Marion donned multiple wigs (including a balding, orange one for the end of Edith's life) and let the makeup team remake her face.

4. Bill Skarsgård as Pennywise the Clown, "IT"

Can you say holy forehead prosthetic? Skarsgård is actually quite attractive (like his brothers) in real life, which is why I was so shocked to learn he was the demented killer clown from IT. Pennywise's creepy eyes weren't hard to accomplish, however, as Skarsgård has a lazy left eye!

3. Jared Leto as Rayon, "Dallas Buyers Club"

Leto lost a concerning amount of weight to play transgender HIV/AIDS patient, Rayon. In the end it paid off because his performance was applauded immensely.

2. Naomi Grossman as Pepper, "American Horror Story"

I'll just leave this one here, no explanation is needed for why this is placed so high.

1. Brad Pitt as Benjamin Button, "The Curious Case of Benjamin Button"

Height difference? Check. Extreme age difference? Check. Nearly unrecognizable? Check!