They call it "acting" for good reason, but physically transformative roles transcend the usual definition. Disappearing behind an outlandish costume or prosthetics can sometimes create entirely new people. Actors often talk about costumes that allow them to get into character more easily. When the costume leaves little trace of the person in it, it can get even easier.

Actors have been disappearing into character for a long time. Since the movies rose to prominence near the beginning of the 20th century, costumes (and actors) have evolved quite a bit. The old days of caked-on makeup have been replaced by digital enhancements and technologically advanced design. (Have you seen the Avengers' costumes?)

However, there's still plenty of modern movies that embrace the hands-on approach to costume design, makeup, hairstyling, and prosthetics. It's certainly not rare for a famous thespian to disappear behind a costume. These are the best examples over the years. You know the actors, but you may not recognize them in costume.