A person who is very awkward and acts very odd. A mothernyucka also says the same things over and over in attempt to be social but ends up being more awkward. They are also very full of themselves and love to admire themselves whenever they can. They are usually really huge perverts as well.
Hahaha look at that kid. He's trying soo hard to be cool but hes just pissing everybody off and being a mothernyucka