Turn 1: Bird Brain
Turn 2: Power of Fire, gg?

There are way too many cards to make this card explode as it is.

That aside, I just noticed WotC actually went with that 'any target' nonsense and has even updated the oracle cards. Wow.

Agree on the danger. A small mana cost would fix it. Making it "Any other bird you control" makes it a 3-card combo and then sure; go nuts.

I'm assuming the restriction on the bottom is to try and stop you mass-milling yourself? It's not very good at it.

It should just be "untap another target tapped bird." I think that's the normal template, and accomplishes what you want

Well, ok; risky for sets that reward you having things in your graveyard, or the lab maniac, but maybe not a problem?

Edit: I missed that this required a tapped bird for a target. While the combo with anything that taps as a cost to dump 30 cards in your graveyard is still damn good, whatever the bird is doing 30 times is probably more dangerous.

Turn 1: Birds of Paradise
Turn 2: This, and you can combo off immediately with 30+ mana + Psionic Gift or whatever.

Even Keeper of the Nine Gales begins to sound nasty.

EDIT: How about?

> Whenever ~ attacks, bury the top card of your library, then untap target Bird.