Dandân

This creature can't attack unless defending player controls an Island.
When you control no Islands, sacrifice this creature.

Auratog

Sacrifice an enchantment: This creature gets +2/+2 until end of turn.

Flying Men

Ghost Ship

Flying
{U}{U}{U}: Regenerate this creature.

Giant Oyster

You may choose not to untap this creature during your untap step.
{T}: For as long as this creature remains tapped, target tapped creature doesn't untap during its controller's untap step, and at the beginning of each of your draw steps, put a -1/-1 counter on that creature. When this creature leaves the battlefield or becomes untapped, remove all -1/-1 counters from the creature.

Leviathan

Trample
This creature enters tapped and doesn't untap during your untap step.
At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap this creature.
This creature can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)

Lord of Atlantis

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Merfolk Assassin

{T}: Destroy target creature with islandwalk.

Mistform Ultimus

Mistform Ultimus is every creature type (even if this card isn't on the battlefield).

Ovinomancer

Sheep

When this creature enters, sacrifice it unless you return three basic lands you control to their owner's hand.
{T}, Return this creature to its owner's hand: Destroy target creature. It can't be regenerated. That creature's controller creates a 0/1 green Sheep creature token.

Pirate Ship

This creature can't attack unless defending player controls an Island.
{T}: This creature deals 1 damage to any target.
When you control no Islands, sacrifice this creature.

Prodigal Sorcerer

{T}: This creature deals 1 damage to any target.

Celestial Dawn

Lands you control are Plains.
Nonland permanents you control are white. The same is true for spells you control and nonland cards you own that aren't on the battlefield.
You may spend white mana as though it were mana of any color. You may spend other mana only as though it were colorless mana.

Psionic Blast

Psionic Blast deals 4 damage to any target and 2 damage to you.

Sindbad

{T}: Draw a card and reveal it. If it isn't a land card, discard it.

Stormscape Familiar

Flying
White spells and black spells you cast cost {1} less to cast.

Time Spiral Timeshifted