An evil bitch that lives in the sky, punishing those who do the most minor of things with something a thousand times worse.
*Boy accidentally trips up friend*
Boy: 'Oops. Sorry'
*Miraculously a piano falls from the sky crushes his feet so he's unable to move, suddenly a pack of dogs emerge out of nowhere attack him; tearing all his clothes off, whilst a bunch of escaped horny convicts pass by, see their chance and have their way.*
Friend: Karma's a bitch