Modarga, the Cursed Tree

Trample, Deathtouch
At the beginning of your upkeep, you may sacrifice a creature. If you do, Modarga gets +X/+X until end of turn, where X is the sacrificed creature's power. The next time you take damage, gain X life, where X is that sacrificed creature's power.
She felt every being's soul inside her, bringing her closer to insanity.