Noblewoman's Laugh

Anime & Manga

 * Sailor Moon:
 * Green Esmeraude does this a lot.

Western Animation

 * OK K.O.! Let's Be Heroes: In "The So-Bad-Ical", Miss Quantum does an evil laugh when she reveals she's a former villain, the Bad Apple.
 * Steven Universe:
 * Sardonyx does this twice in her introductory episode. Bonus points for doing the pose both times as well. She's not evil or mean, but she is quite a showoff.

Western Animation

 * Steven Universe: Lars lets out a smug giggle in "Lars of the Stars" to taunt a foe, complete with holding his hand below his mouth. It's one of several flamboyant mannerisms he adopted after becoming a Space Pirate.