I was thinking about an enemy for alpha survival mode that could fly like an evil bird or dragon or somethin like that i already know of those jellyfish things in the nether but i think the normal minecraft world needs a flying enemy of some sort
No offence man, but you do know we're in Beta now, right?
But on topic, there are a few mods out that provide some flying mobs, they're not too bad.
Just need to wait for the creators to update them for the latest version of Minecraft.
Why don't you give them a go?