Bitchmeister is the bitch of bitches. Meister is the German word for master. Bitch can mean basically anything based on the context. It can be very negative and very positive.
Bitchmeister is also a person calling others bitches. See e.g. the bitchmeister blog on hans-jschmid.com, a German blog where a guy calls others bitches and "my bitches".
n. (from English "bitch" for female dog, and German "Meister" for master). A woman who is the worst-tempered, schemingest, full-of-herself, back-stabbingest waste of human flesh imaginable.
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).