The Mysterious Egg

Some of the other possibilities, however, are pretty dang cool.
First of all, there's 4 companion vanity pets that could hatch out of the egg: A Cobra Hatchling, a Tickbird Hatchling, a White Tickbird Hatchling, or a Proto-Drake Whelp. All 4 are likely to be highly desired centerpieces of a companion collector's set, and I know a few dragon enthusiasts in particular who are especially drooling over that last possible pet.
The Disgusting Jar from the Frenzyheart definitely has a lot of catching up to do. It may be that eventually someone will find something in it that would make up for missing out on 4 extra pets and a mount, but for now, It's Oracle reputation for me for sure.
 Speaking of Dragon enthusiasts, there's one more possible hatching from the egg that MMO-Champion discovered recently: The Green Proto-Drake. That's right, get revered with oracles, carry around an egg for a few days, and you could have an awesome looking green dragon lizard thing to ride around on.