The Norf Nags were a seemingly fictional group of people whom Dreamy had encountered in "The Smurf Who Would Be King" where they served as the main antagonists. They lived in a cavernous region somewhere above where the Pookies lived, using various scare tactics such as shadow casting, megaphones, and their quake-making machines to force the Pookies to make them mine and deliver valuable gems unto them.
Though at first Dreamy was scared by the Norf Nags just as the Pookies were, he eventually gathered the courage to enter their realm and expose them for the rather weak and less intimidating people they really were, thus freeing the Pookies from their tyranny before the quake-making machines caused Dreamy to bump his head, returning him back to the Smurf Village where he was still on board the S.S. Smurf II, all safe and sound.
Papa Smurf told Dreamy that what he experienced was a dream, but as Dreamy had found a crystal lying on the ground near the S.S. Smurf II, he began to wonder if it really was a dream.
