Invocation of Darkroot

Creatures with death counters cannot be affected
by a spell or ability you control.
Whenever a creature enters the battlefield, you
may place a death counter on target creature.
If a creature dies, target player receives X poison counters where X is the number of death
counters that were on the creature.
"The forests of Zendikar are so lively. We seldom
remember the bodies just beneath the roots."
-Sova Sorai