Plot: John Lithgow breaks down his most iconic characters, including his roles in 'Shrek,' '3rd Rock From The Sun,' 'Dexter,' 'Harry & the Hendersons,' 'The Crown,' 'Footloose,' 'Cliffhanger,' 'The Changing Room,' 'Bombshell,' 'The Old Man,' 'M. Butterfly' and 'The World According to Garp