Valkyrie of Natural Deaths

Whenever a nontoken creature you control dies you may put a corpse counter on Valkyrie of Natural Deaths and gain 1 life.
{b/g}{b/g}, {t}, Remove any amount of corpse counters from Valkyrie of Natural Deaths: Draw a card and lose 1 life for each counter removed this way.
As long as there are three or more corpse counters on Valkyrie of Natural Deaths it has hexproof.