Avacyn, Future's Unwritten

Flying, indestructible
Suspend 4 -{w}{b} (Rather than cast this card from
your hand, pay {w}{b} and exile it with four time
counters on it. At the beginning of your upkeep,
remove a time counter. When the last is removed, cast
it without paying its mana cost.)
Whenever a time counter is removed from
Avacyn, Future's Unwritten while it's exiled,
create a 3/3 white Angel creature token with
flying.