Prosperous Pirates

When Prosperous Pirates enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Pirate Hat

Equipped creature gets +1/+1 and has "Whenever this creature attacks, draw a card, then discard a card."
Equip Pirate {1}
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Warkite Marauder

Flying
Whenever Warkite Marauder attacks, target creature defending player controls loses all abilities and has base power and toughness 0/1 until end of turn.

Island

Burdened Aerialist

When Burdened Aerialist enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a token, Burdened Aerialist gains flying until end of turn.

Malcolm, Keen-Eyed Navigator

Flying
Whenever one or more Pirates you control deal damage to your opponents, you create a Treasure token for each opponent dealt damage. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Partner (You can have two commanders if both have partner.)

Corsair Captain

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Other Pirates you control get +1/+1.

Kitesail Corsair

This creature has flying as long as it's attacking.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Sea Legs

Flash
Enchant creature
Enchanted creature gets +0/+2 as long as it's a Pirate. Otherwise, it gets -2/-0.

Admiral's Order

Raid — If you attacked this turn, you may pay {U} rather than pay this spell's mana cost.
Counter target spell.

Merchant Raiders

Whenever Merchant Raiders or another Pirate you control enters, tap up to one target creature. That creature doesn't untap during its controller's untap step for as long as you control Merchant Raiders.