Water Elemental

Giant Tortoise

This creature gets +0/+3 as long as it's untapped.

Mana Vault

This artifact doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap this artifact.
At the beginning of your draw step, if this artifact is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Siren's Call

Cast this spell only during an opponent's turn, before attackers are declared.
Creatures the active player controls attack this turn if able.
At the beginning of the next end step, destroy all non-Wall creatures that player controls that didn't attack this turn. Ignore this effect for each creature the player didn't control continuously since the beginning of the turn.

Sea Serpent

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

Creature Bond

Enchant creature
When enchanted creature dies, this Aura deals damage equal to that creature's toughness to the creature's controller.

Segovian Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Island Fish Jasconius

This creature doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {U}{U}{U}. If you do, untap this creature.
This creature can't attack unless defending player controls an Island.
When you control no Islands, sacrifice this creature.

Counterspell

Island

Jump

Target creature gains flying until end of turn.

Phantasmal Terrain

Enchant land
As this Aura enters, choose a basic land type.
Enchanted land is the chosen type.

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.)