Uncanny Calm

At the beginning of each player's end step, if no creatures attacked that turn, put a calm counter
on Uncanny Calm.
{3}{g}, Remove a calm counter from Uncanny
Calm: Create a 4/4 green Elemental creature token with trample.
{x}{g}{g}, Remove X calm counters from Uncanny Calm: Put X +1/+1 counters on each creature you control.