As badass as that sounds, I imagine it could be a bit of a pain in the ass, being all that big. =O I mean... you encircle the entire planet you live on. Not much space to move around.
Personally, I'd be either Nidhöggr or a Lich.
Nidhöggr:
I get tosmokegnaw the roots of Yggdrasil while trolling some eagle perched in its branches. I bring an army of corpses back from the dead during ragnarok, plus I actually survive ragnarok.
Lich:
I am immortal, am capable of powerful magic and can create my own little zombie apocalypses whenever I feel bored. What could possibly go wrong?