Muahhahaha
An evil laugh. A laugh one does when they are about to do something evil. Such as when a villan has a plot to take over the world, he does this laugh right before it goes into effect. Also a noise made by people who have just gotten away with an evil deed or crime.
Finally, the world is mine! Muahhahaha!
Muahhahaha
A word used when implying that you are plotting something evil.
I have an evil plot. Muahhahaha!!!