rhyming slang a clue: I don't have a scooby doo what you're talking about Often shortened to: scooby
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
How to use scooby doo in a sentence
The composite photo whose eyes follow you around the room are less Matthew Lewis or Sheridan Le Fanu than “Scooby-Doo.”
That was my first movie, so I was totally green, and he was at the height of his scooby doo craziness.Diane Kruger on ‘The Bridge,’ the Immigration Problem, and Rooting For Germany in the World Cup | Marlow Stern | July 10, 2014 | THE DAILY BEAST
Plus, if you have kids, you may recognize her as Velma in the live-action Scooby-Doo movies.The Most Random Old TV Stars to Appear on ‘Mad Men’ | Kevin Fallon | May 29, 2014 | THE DAILY BEAST
The dog might even have been drugged (we might call this the scooby doo explanation).
It was that Oogie Boogie was actually Dr. Finkelstein in disguise—sort of a Scooby-Doo sort of ending.Henry Selick on Directing ‘The Nightmare Before Christmas’ | Marlow Stern | October 29, 2013 | THE DAILY BEAST