A variation of "OH SNAP" typically used alongside spoilers either as an accompaniment or a response. Refers to the video of a man driving by a release party of Harry Potter and the Half-Blood Prince and screaming "Snape kills Dumbledore" at random passerby.
"So he was all, 'Snape kills Dumbledore, Spike dies, dyke spies, etc.' to me, and I was like, "OH SNAPE!'"
by Mel December 10, 2005