Is it possible to animate a mask? Haven't had any luck. What method should I utilize?
Absolutely! I'm not sure what you're trying to accomplish, but you can have a view whose superView acts as a mask, and then animate both of them independently (or in unison). One example would be a square photo on a grid animating to a full screen, portrait photo in a lightbox.
Thanks, Josh Puckett ..a good example of what I'm referencing would be Twitter's iOS7 app and the transition that occurs when you tap on an image in your stream openning to a lightbox view.