Valgavoth, the Lifeline is a rare Legendary Creature — Insect Angel card from Alchemy: Reality Fracture (YFRA), collector number 3.
Flying Whenever you gain life, creature cards in your hand and graveyard perpetually get +1/+1. As long as you've gained life this turn, you may cast creature spells from your graveyard. If you cast a spell this way, that creature enters with a finality counter on it.