Some look-alikes are more well documented than others.
If you're a celebrity gossip reader, you've likely noticed a Zooey Deschanel-Katy Perry resemblance. Or can at least picture that now that we've mentioned it.
Other celeb doppelgangers, however, are less obvious.
Have you ever noticed the similtarities between Jason Segel and Peter Jackson? Elijah Wood and Mischa Barton? Scarlett Johansson and a young Christoper Walken?
Neither did we, until we saw this cool video. Take a look: