Ixalan

Headwater Sentries | Creature | Merfolk Warrior | | Naomi Baker

Prosperous Pirates | Creature | Human Pirate | When Prosperous Pirates enters the battlefield, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.") | Josh Hass

Sailor of Means | Creature | Human Pirate | When Sailor of Means enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.") | Ryan Pancoast

Shaper Apprentice | Creature | Merfolk Wizard | Shaper Apprentice has flying as long as you control another Merfolk. | Yongjae Choi

Shipwreck Looter | Creature | Human Pirate | Raid — When Shipwreck Looter enters the battlefield, if you attacked this turn, you may draw a card. If you do, discard a card. | Wayne Reynolds

Shore Keeper | Creature | Trilobite | {7}{U}, {T}, Sacrifice Shore Keeper: Draw three cards. | YW Tang

Siren Lookout | Creature | Siren Pirate | Flying When Siren Lookout enters the battlefield, 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 or put it into your graveyard.) | Chris Rallis

Storm Sculptor | Creature | Merfolk Wizard | Storm Sculptor can't be blocked. When Storm Sculptor enters the battlefield, return a creature you control to its owner's hand. | Sidharth Chaturvedi

Watertrap Weaver | Creature | Merfolk Wizard | When Watertrap Weaver enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step. | Josu Hernaiz

Wind Strider | Creature | Merfolk Wizard | Flash Flying | Magali Villeneuve