scooby doo ( verb / noun )

to go "scooby do:" to twist the head in an upward "rrrRRRRR!!" motion, at the same time saying "rrrRRRRR," having just realized the obvious.

"Dude,when he realizes that's not a bottle of Corona, he's gonna' go scooby doo.

by Rev. Dr. Swami Sez August 1, 2005