Stubborn Stag

Stubborn Stag enters the battlefield with a
+1/+1 counter on it.
{t}, Remove a +1/+1 counter from Stubborn
Stag: Add one mana of any color.
When Stubborn Stag attacks, if it has no +1/+1
counters on it, put a +1/+1 counter on it. You
may then pay {g/w}{g/w}, if you do put an additional
+1/+1 counter on it.