He is who you think he is, except...
Bryan Cranston, who stars on the hit TV show Breaking Bad, wanted to go on the floor and mingle at the San Diego Comic Con convention, but he knew he'd be mobbed if he walked around as himself. Luckily, he'd found an amazingly realistic full-head mask of his character Walter White, so he walked around pretending to be an ordinary person pretending to be Walter White.
One of these is not acting.
Bryan Cranston on David Letterman, including
shots of him wearing the mask at Comic Con
Bryan Cranston on Jimmy Fallon, where he shows the
actual mask he wore, and lets Jimmy don his head.