Common Sense Note
Parents need to know that everything is topsy turvy when Elmo ventures into Grouchland, so a certain understanding of what is (and isn't) acceptable behavior is needed to get the humor fully -- hearing the pleasure with which the Grouches tell each other to get lost is funny only if you know it's not really OK. There are a few mildly perilous/tense moments that could upset sensitive or very young viewers, and some kids may be concerned that Elmo doesn't seem to have any parents and could need some reassurance.
The Queen of Trash is a curvaceous, sensual woman. Huxley is shown in his boxer shorts and an undershirt.
Some perilous moments -- like a rollerblading scene and falling down a tunnel -- that might put little ones on the edge of their seat. The villain, Huxley, is a selfish meanie who sends Elmo into a dark tunnel after stealing his blankie. But Elmo asks his friends in the audience for help and escapes the dark place.
Grouches aren't models of friendly language. Part of their "charm" is saying "scram," "yuck," and "go away!"
As per usual, the friends on Sesame Street come in many colors, shapes, and sizes, and everyone pretty much gets along (except for the grouchy characters in Grouchland, of course).
Elmo has lots of toys in his room, including some Fisher Price classics and a poster of Tiger Woods. Huxley sings a song about things that he wants to take from other people in which he names brands like Atari and Ferrari. There's a reference to Starbucks, though it's called "Tarbucks."
Drugs / Tobacco /