A quicky based on a conversation Tom and I had a year ago.
Galactus is a problem. In comics he's fantasic, a giant purple techno-demi-god that stands around vaguely menacing planets. When it comes to translating him into movie form, or even movie-caliber comic form (Ultimate: Galactus) he's been turned into a space-dust-storm and swarm of giant metal bugs respectively.
Tom suggested I read up on his backstory, and it turns out that Galactus is the only living creature to have lived before our universe and survive the big bang.
We may have been a little hopped up on Hellboy, but we started thinking it would be great if Galactus looked alien, ancient, and gargantuan. He could be loosely human shaped, enough that legends of him could have mistaken him for a massive man.