1. Chewbacca (Star Wars)
The role of Chewbacca turned out to be a defining one for 7ft 3 Peter Mayhew, but the Surrey-born actor had some tough times making the original trio of Star Wars movies while wearing a thick, fluffy costume made from a mixture of goat and yak hair.
Not only did Mayhew have to worry about overheating under all that fur, he also had to do his best to keep the costume as clean as possible. Whenever it got a little wet, the outfit would develop a horrible odour, and it's actually possible to see Mayhew actively trying to avoid getting dirty during the memorable trash compactor scene in the first Star Wars movie.
The intense heat generated within the suit also caused the face to sometimes slip out of line with Mayhew's eyes, resulting in a pretty ghoulish sight and several retakes. Fortunately, when it came time to make the prequels and Mayhew was called back in for Episode III: Revenge of the Sith, the suit had been adapted to involve a cooling system.