Mountain

Fathom Fleet Captain

Menace
Whenever Fathom Fleet Captain attacks, if you control another nontoken Pirate, you may pay {2}. If you do, create a 2/2 black Pirate creature token with menace.

Wanted Scoundrels

When Wanted Scoundrels dies, target opponent creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Dire Fleet Poisoner

Flash
Deathtouch
When Dire Fleet Poisoner enters, target attacking Pirate you control gets +1/+1 and gains deathtouch until end of turn.

Lightning-Rig Crew

{T}: Lightning-Rig Crew deals 1 damage to each opponent.
Whenever you cast a Pirate spell, untap Lightning-Rig Crew.

Walk the Plank

Kitesail Freebooter

Flying
When Kitesail Freebooter enters, target opponent reveals their hand. You choose a noncreature, nonland card from it. Exile that card until Kitesail Freebooter leaves the battlefield.

Daring Buccaneer

As an additional cost to cast this spell, reveal a Pirate card from your hand or pay {2}.

Swamp

Dire Fleet Captain

Whenever Dire Fleet Captain attacks, it gets +1/+1 until end of turn for each other attacking Pirate.

Fathom Fleet Boarder

When Fathom Fleet Boarder enters, you lose 2 life unless you control another Pirate.