Trivia: In one of the intros used in season 1 on TV you can see a clip of Ross, Chandler and Joey dancing in Ross' apartment. That clip is not in any aired episode. It's in the extended version of "The One with All the Poker".
Superskrull - S1-E7
Trivia: The Godzilla parody movie that the Skulls are watching at the beginning of the episode says it is presented by Roger Shnorman. This is a reference to cult-film director Roger Corman, who himself was an executive producer on a Fantastic Four film that was made around the same time this series aired, but was deliberately never released. (00:01:30)