Olaf, the Berserker

Menace, Endure 3 (At the beginning of your
end step, if a source controlled by an opponent dealt
damage to this creature this turn, put 3 +1/+1
counters on it.)
Whenever Olaf, the Berserker deals combat
damage to a player, untap each Berserker
and Barbarian you control that attacked this turn.
After this phase, there is an additional combat
phase.