Barbara, the Guardian Spirit

Whenever Barbara, the Guardian Spirit enters
the battlefield or attacks, you may cast a spell
with converted mana cost 3 or less from your
hand without paying its mana cost.
If Barbara would be destroyed, exile it with three
time counters on it instead and it gains suspend.
At the beginning of your upkeep, remove a time counter. When the last is removed, return
Barbara to the battlefield under its owner's
control with a +1/+1 counter on it.