This is pretty funny. Its from the American version of "Whose Line I It Anyway?", an improvisational comedy that was popular in the UK during the 90s but I don't ever remember it being this good. With special guest star Robin Williams.
NB for anyone who, like me, asn't got a clue who Carol Channing is, here is her Wikipedia page. Basically, she's an American musical actress with a distinctive voice and appearance.