Evil laughter
An evil laugh is a stock megalomaniacal laugh by a villain in fiction. In comic books, where supervillains utter such laughs, it is variously rendered as mwahaha, muhuhahaha, muwhahaha, fwahahahahahahahehehehehehehe, or booWAHAHA.. (Compared to Ho ho ho.) These words are also commonly used on internet Blogs, BBSes, and games. There, they are generally used when some form of victory is attained, or to indicate superiority over someone else. The words are often used as either interjections or less frequently, as nouns.
For men it starts off as a low rumbling, in the back of the throat, slowly ascending to a loud cackle. For women, on the other hand, it begins as a hoarse scratchy sound, and then rises to a maniacal laugh- however, this could work either way. Some protagonists have been known to use an "evil" laugh, either as a product of mental instability or merely to display a feeling of significance as a villain would. Father Grigori from the video game Half-Life 2 is an example of this. [1] [edit]
Murray the Demonic Talking Skull from the video game "Monkey Island" also uses this type of laughing a lot.
The Evil Overlord List notes that evil laughter often distracts the villain from important details that the hero can use to escape or prevail.