ouroboros

Bloodcost 2 Whenever you sacrifice Ouroboros, put an Indestructible counter on target land you control, then put Ouroboros back into your hand and attach an omen counter to yourself. {G}: Ouroboros gains trample and +X/+X until end of turn, where X is the amount of lands you control with Indestructible counters.{/fontsize-17}