мудак"

Apparently calling a Russian plutocrat a Mudak is about the worst thing a Russian will call another Russian.  

муди" or MUDAK translates into American English as:
horse's ass, asshole, dickhead, moron, motherfucker, turd, blockhead, shitass, simpleton" but to Russians it apparently has a deeper meaning.
I was going to use:   "Мои яйца больше твоих"
(my balls are bigger than yours)

but apparently that does not mean anything to Russians.

• Funny how what we take for normal everyday life, to other people in other places it can seem so alien and visa versa.