Occurances of the "H" word in Muppet productions:
The Muppet Show pitch reel originally ended with Kermit entering, looking at the camera and asking, "What the **** was that?"
It is used on The Muppet Show during "The Devil Went Down to Georgia."
During the "Happiness Hotel" number in The Great Muppet Caper: "Still, the management is cheerful, though the whole joint's gone to ****."
Long John Silver says it toward the end of Muppet Treasure Island.
Occurances where the "H" word is used as part of a pun:
On The Jim Henson Hour, when Fozzie fills in as weather man on the Today Show, while looking at the weather map, he says: "There's a giant L over here near Nebraska! All you people in Nebraska -- you STAY in your HOMES until we can find a way to get the L out of there!"
A similar joke was also used on a recent episode of Sesame Street (the one with Tina Fey and the Bookaneers).
On Muppets Tonight, the infamous (there's that word again) "Elefino" joke.