Place it at the end of a reveal scene, just before the reaction shot, then follow it with a short laugh or a gasp for contrast. For a bigger build-up, open with the Law and Order Dun Dun cue and save this cartoon version for the payoff.
About this sound
This is a drawn-out dun-dun-dunnnnn sting in the bright, cartoon style of the Mickey Mouse shorts, with three low notes that stretch the final one for comic effect. It lands as mock-serious suspense, turning a small reveal into a melodramatic moment. The version here follows the Mickey Mouse shorts take on the classic dramatic cue.