At the MuppetFest! convention being held shortly to celebrate the 25th anniversary of The Muppet Show, there will be spectacles galore. Squealing children... eye-popping exhibitions... heartwarming performances. But perhaps no sight at the Pasadena (Calif.) Civic Center will prove to be as memorable, or as poignant, as that of a little bird with purple plumage, a crooked beak and a fearless gleam in his eye that he probably would never realize all heroes possess. That's right Gonzo the Great may not be able to fly, but, by always aiming for the clouds, in his own unique way, he soars.