Bosco, The Best

You may cast this card for {2}{w} instead of its mana cost if you control no creatures and have less than 4 other cards in your hand.

Whenever Bosco becomes tapped, choose one that hasn't been chosen
• Create a treasure token and draw a card.
• Put a shield counter on a creature that doesn't already have one.
• Put Bosco on top of its owner's library.
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Stay by my side, Bosco!