I always thought it would be cool if there were a story where Galactus saw something in a really cheesy villain that no one else saw and so he called upon him and amped him up... Someone like Paste Pot Pete
And Galactus is proved wrong when the character just seizes the opportunity and attacks his regular arch rival (IE Spiderman, Fantastic Four, etc) And Galactus then has to strip his power.
So:
Paste Pot Pete
The Owl
Stilt Man
The Slide
Chronos (The Dude that throws Sun Dials)
The Vulture
Classic Hyperion.
Having a full time Superman-esqe herald would be great and since he is inherently good, becoming Galactus' herald would be a great source of internal conflict for the character. Plus, Supreme Power made this version of Hyp pretty much obselete anyway.
Every now and again Galactus slip and calls him "Kryptionian"