Atraxa, Voice of Vitality

Flying, vigilance, deathtouch, lifelink
Whenever Atraxa, Voice of Vitality enters the battlefield or attacks, put a +1/+1 counter on
each creature you control.
Whenever one or more creatures you control
attack a player with three or more poison
counters, you may pay {w}{u}{b}{g}. If you do, proliferate. (Choose any number of permanents
and/or players, then give each another counter of
each kind already there.)