A stunt double is a type of body double who acts as a skilled replacement for the actors so they don't get injured on set. The stunt doubles do all the shit the real actor couldn't do without getting killed - such as jumping out of a building or crashing a car. The doubles are dressed up like the actor or actress and are usually of similar size...and way less hot.
Here are some of the worlds famous actors with their stunt doubles. Megan Fox is looking at her stunt double like "this bitch ain't as hot as me"