Skarn, Hewer of Ancient Lands

Skarn, Hewer of Ancient Lands enters the battlefield with 3 Stalagmite counters on it.
{r}, Sacrifice a land: Put a Stalagmite counter on Skarn, Hewer of Ancient Lands.
{g}, Remove a Stalagmite counter from Skarn, Hewer of Ancient Lands: Regenerate Skarn, Hewer of Ancient Lands.
{1}{r}, Remove a Stalagmite counter from Skarn, Hewer of Ancient Lands: Deal 2 damage to target creature.