For some reason today I've had a hankering to watch some of my favourite old Muppet Show sketches, and while poking around on YouTube I stumbled on one that was always near the top of my list: the episode where Fozzy, Scooter and the gang get their hands on an instructional book for would-be superheroes.
Over the course of the show, various costume-clad Muppets try everything from swinging on ropes to seeing through doors to jumping off ladders in the belief that they can fly. Just hilarious when I was a kid and still pretty funny now.
The "mastering abilities" sequences in Spiderman and Iron Man owe a lot to this episode of the Muppets.
The clip I've linked to above is a montage put together for a "remember when" sequence in a later episode, but the original scenes were from Linda Carter's turn hosting the show, I think. (which is another reason to seek out the original episode, 'cause hey, who doesn't like looking at Linda Carter?)