coo coo kachoo Share definition Flag A mispronunciation of a line from I am the Walrus. "Coo coo Kachoo" "It's 'GOO GOO G'JOOB,' you idiot!" coo coo kachoo by nobodyinparticular April 2, 2007 0 0 Get merch Get the coo coo kachoo mug. Buy Now — $32.95 See more merch