Strolling Down Memory Lane Without a Ding-Dong Thing on My Mind

After I read Adam's post about Kaptain Kool & the Kongs (and the rest of the Krofft Supershow), and Kalinara's reminiscences about Siegfried & Roy: Masters of the Impossible and BraveStarr, a halfway-forgotten memory of a show from my own youth came bubbling to the surface...but only partially so.

"Captain Hero" was a recurring sketch on some kids' show (though I can't remember which one), about a young boy who would don a mask and cape and go into action whenever trouble reared its ugly head (though he had no powers). I remember that one of his friends always wore a paper bag over his head (this character may have been part of the other sketches as well). The only specific episode I can recall had Captain Hero facing off against a bully who was trying to steal bag-head-boy's bicycle; he scared the bully off by claiming that the bike was radioactive (and bag-head-boy backed up the bluff by hinting that he wore the bag because he'd been mutated by it). Yes, it was that kind of show.

The one thing I do remember vividly was the theme song:

Captain Hero!
Captain Hero!
Faster than a rock!
Stronger than a frog!
Smarter...
Than a piece of pie!
What a guy!

So, does anybody else recall this, and can you tell me what show it was part of?