Butchers of Otaria

Fierceness X, where X is equal to the number of
creature and/or planeswalker cards that were put
into an opponent's graveyard from the battlefield
this turn (Whenever Butchers of Otaria deals lethal
damage to a permanent, put X +1/+1 counters on it.)
Whenever Butchers of Otaria attacks, it deals
damage equal to the number of counters on it to
up to one target creature or planeswalker.