What's the Big Frigin' Difference?!

You know the deal... now get to huntin'! **HINT -- There are three differences in the above photographs!**

Source: http://www.tmz.com/2012/04/29/whats-the-big-frigin-difference-photoshop-celebrity-hunt-guess-tmz-games/

Harry Houdini Rock Hudson Engelbert Humperdinck Mary Beth Hurt Lauren Hutton