Not on Instant, but it is on Netflix and
well worth it. It's called Behind the Mask: The Rise of Leslie Vernon.
It's presented as a documentary (though it is not) about Leslie Vernon, an aspiring serial killer/slasher movie villain. Very clever, and awesome if you're a fan of slasher movies.
Link:
http://movies.netflix.com/WiMovie/Be...?trkid=2361637