"Never poke a thorg; you're likely to get mauled", is one of those pieces of wisdom parents are wont to throw out. Thorg are tiger-like creatures, excepting they are half again as long and possessed of eight limbs versus four. They also have a nasty disposition.
"A black blade in the queen's court" is a swords and dragons reference to a very powerful but pretty rare hand. Good to have; very advantageous but hard to setup. Its used the same way in speech.