Faerie Impostor

Flying
When this creature enters, sacrifice it unless you return another creature you control to its owner's hand.

Illusionary Servant

Flying
When this creature becomes the target of a spell or ability, sacrifice it.

Alluring Siren

{T}: Target creature an opponent controls attacks you this turn if able.

Aven Fleetwing

Flying
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Merfolk Mesmerist

Aether Figment

Kicker {3} (You may pay an additional {3} as you cast this spell.)
If this creature was kicked, it enters with two +1/+1 counters on it.
This creature can't be blocked.

Kraken Hatchling

Stealer of Secrets

Whenever this creature deals combat damage to a player, draw a card.

Seacoast Drake

Calcite Snapper

Shroud (This creature can't be the target of spells or abilities.)
Landfall — Whenever a land you control enters, you may switch this creature's power and toughness until end of turn.

Merfolk Spy

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever this creature deals combat damage to a player, that player reveals a card at random from their hand.

Cloud Elemental

Flying
This creature can block only creatures with flying.

Fortress Crab

Phantasmal Bear

When this creature becomes the target of a spell or ability, sacrifice it.