You learn to just embrace the bitch label. It's the only way to get through it -- you're going to get called one whether you are or not, so you might as well own it and make it work for you. I'm actually a very nice person and treat my employees wonderfully but I've been told scare the shit out of certain people who don't know me very well. My reports have actually told me they love my reputation; they promote it so that 1) they get what need from other departments easier and 2) they don't have people fighting to get their jobs (I have by far the best department/division/employees).