Ragemoth Skullbasher.

Mythical (you can only have one copy of this card, in
your deck and in the battlefield)
All warrior creatures you control are beserkers
and vise versa, they have haste. All creatures your opponents control are cowards.
Whenever Ragemoth attacks, all warriors you
control gain +2/2 and indestructible, and all beserkers you control gain+2/+2, and lifelink
this turn.