1. A character from the television show Glee; a particularly evil cheerleading coach whose single goal in life is to destroy the glee club.
2. The subject of a series of Chuck Norris-esque jokes.
Sue Sylvester doesn't have a "ctrl" button on her computer, Sue Sylvester is always in control. OR There is no such thing as natural selection, only things Sue Sylvester allows to live.