The pirates had ventured into the interior for treasure. They found something far greater.

Dowsing Dagger // Lost Vale

(Transforms from Dowsing Dagger.)
{T}: Add three mana of any one color.

When Dowsing Dagger enters, target opponent creates two 0/2 green Plant creature tokens with defender.
Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a player, you may transform Dowsing Dagger.
Equip {2}

The List

XLN Treasure Chest

Ixalan Promos

Ixalan

When Dowsing Dagger enters the battlefield, target opponent creates two 0/2 green Plant creature tokens with defender.
Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a player, you may transform Dowsing Dagger.
Equip {2}

Attacking with an equipped creature doesn’t cause Equipment attached to it to become tapped. Dowsing Dagger will normally be untapped when it transforms into Lost Vale.

For more information on double-faced cards, see the Ixalan mechanics article (http://magic.wizards.com/en/articles/archive/feature/ixalan-mechanics).