Gambling Goblin

{t}, Flip 2 Coins: For each time the coin turns up
heads, choose one:
- Put a colorless Gold artifact token into play.
It has "Sacrifice this artifact: Add one mana of
any color to your mana pool."
- Put a +1/+1 counter on this creature.
If you use this creature's ability and come up
with no heads, sacrifice this creature.