What is the meaning of 'Muhahahaha?

Answer 1

It is an attempt to spell the sound of a spooky laugh.

More information from Wikipedia:

Evil laughter or maniacal laughter is a stock manic laughter by a villain in fiction. In comic books, where supervillains utter such laughs, it is variously rendered as mwahahaha, muwhahaha, muahahaha, bwahahaha, etc. (Compared to Ho ho ho). These words are also commonly used on internet Blogs, Bulletin board systems, 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. An evil laugh is often entertaining for friends because each one may be unique.

(For more on the history of these evil laughs - as well as a link to hear a huge selection of these laughs - see Answers.com via the Related link.)

Answer 2

te mágnes picsájú