Place it just after the ambush is revealed, then follow it with the Roblox Oof Sound for the fallout. To build the threat, open with the Enemy Spotted Sound Effect before the attack, then let this clip answer it. The FNAF Jumpscare Scream works as a final hit after the laugh.
About this sound
This clip packs a squeaky, speeding hahaha-hehehe laugh from the dolphin-riding zombie in Plants vs Zombies into less than a second. It feels frantic, mocking and gleefully unhinged, turning a small blunder into an instant joke. The laugh comes from PopCap's 2009 tower-defence game, where the Dolphin Rider Zombie vaults over the first plant in its lane.