In "The Stuff Dreams Are Smurfed Of", Gargamel's nightmare of the giant Smurfs near the beginning of the episode, and the ending where he gets chased off by a giant Smurf summoned by Papa Smurf using the Crown Of Dreams, is similar to Gargamel's nightmare at the beginning of the Season 7 episode "Sleepless Smurfs", where he meets Papa Smurf outside his house, who was bigger than his Smurf size.
The title "The Stuff Dreams Are Smurfed Of" is derived from a quote talking about dreams, the most famous modern use of the phrase responsible for much of its popularity was at the end of The Maltese Falcon (1941) where the lead hard boiled detective paraphrased a much older expression dating back to William Shakespeare in regard to the titular falcon statue which turns out not to be of great value.