Boba Fett, the Unrelenting

Flying, vigilance
When a creature an opponent controls dies or is
exiled, you may pay {x}{w/b}, where X is the
creature's mana value.
If you do, exile it and place
a bounty counter on it.
At end of turn, if there are 5 or more
bounty counters on creatures your opponents
control in exile, draw a card.