You can animate the dead to make a flying skeleton, as long as that skeleton could fly magically in life. Is there some awesome, easy way to determine if a creature's flight is magical or not? I got together a list of creatures from the 3 Bestiaries, which creatures have "Constant - Fly", but I feel as though some are being left out. Nightmares don't have wings, isn't their flight magical? Nothing in their block talks about it :\ And while I have your attention: Is there an errata or something that makes the Zombie variants officially like the skeletons (double the HD as far as casting Animate Dead goes, etc)?
I'd say that pretty much anything that can fly with out wings has magical flight (unless they are described as a sentient bag of helium or something).
The errata document I have for the Bestiary doesn't mention zombies at all (although I am unsure if I have the newest version).
Yeah, and the only way to see if it have wings or not is to check out the picture. Not foolproof. But I think I'd agree.
Yeah, flight is either an extraordinary ability (physical wings and such), or a supernatural ability (magical). Most of the time, it's pretty obvious which type of flight a creature uses. Other times where it isn't obvious, it'd be up to the GM, since the bestiary doesn't list which type of flight a creature has.