As with any sketch show SNL can be rather hit and miss, though they tend to be hit more than miss. Every year the show seems to capture lightning in a bottle and put out a perfect sketch. Their Grouch sketch has to be one of those perfectly funny moments that will stand the test of time. The joke is that David Harbour is starring in a gritty retelling of Sesame Street one where Oscar the Grouch eventually becomes a joker like figure in a world gone mad.
The idea is already absurd but Harbour plays it in a way that gives the audience plenty of laughs. Copying several key scenes from the Joker Trailers and delivering his performance in a completely unironic way. If you need a laugh then you need to watch this one.