Robbie Coltrane
The actor behind the enormous Rubeus Hagrid character from "Harry Potter" had to undergo a huge transformation to play the part. In the film, Hagrid is taller, wider and thicker than any non-magical human could ever be. To get Coltrane to look like the character, they had to fashion several unique costume pieces for him. Although Coltrane has acted in projects besides "Harry Potter," most fans wouldn't recognize him as Hagrid if you saw him walking down the street.