Tiamat

Flying, vigilance, haste, trample, lifelink
Whenever Tiamat deals combat damage to a
player, reveal that many cards from the top of
your library. Put any number of Dragon creature
cards from among them onto the battlefield and
the rest on the bottom of your library in a
random order.
When Tiamat is put into the graveyard or exile
from the anywhere, return it to its owner's hand
at the beginning of the next end step.