Viridius

Viridius enters the battlefield with a gem counter on it.
{t}, Remove a gem counter from Viridius: Search your library for up to three creature cards and put them onto the battlefield. Then put two +1/+1 counters on each of those creatures and shuffle your library.
{g}{g}, Sacrifice any number of creatures with total power 10 or greater: Put a gem counter on Viridius.