The loud witch cackle is a stock Halloween archetype rather than a line from one specific film, built on the classic image of a broom riding spell caster laughing at her own trick. Short laugh clips like this spread on soundboards and social video because they need no context to be understood. Editors reuse it every October for haunted houses and costume content, and year round for cartoon villains, evil plans and over the top reactions. Its exaggerated tone keeps it funny instead of truly frightening.