Ivysaur

Evolve - {3}{g}{g}: search your library for a card named Venusaur and place it onto the battlefield tapped. Exile Ivysaur.

{2}{g}{t}: place a -1/-1 counter on target creature. Repeat this process on each of its owner's upkeep steps. If a creature dies from this ability, its owner gains a poison counter for each -1/-1 counter on this creature when it died.