Merfolk Treasure-Caller

Whenever a creature you control attacks, it explores (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back on top or into your graveyard.)
Whenever a creature you control explores, create a colorless Treasure artifact token with "{t}, Sacrifice this artifact: Add one mana of any color to your mana pool."