evil laugh

An evil laugh is a theatrical, prolonged bout of laughter meant to signal villainy or malicious intent.

It's a stock element of melodrama and horror, associated with cartoon villains, mad scientists, and anyone relishing another's misfortune.

The classic version involves drawn-out syllables—Mwa-ha-ha-ha! —often accompanied by raised hands or dramatic pauses.

In everyday use, people deploy evil laughs ironically when doing something mildly mischievous: She gave an evil laugh as she took the last slice of pizza.