Reef Worm

When this creature dies, create a 3/3 blue Fish creature token with "When this token dies, create a 6/6 blue Whale creature token with 'When this token dies, create a 9/9 blue Kraken creature token.'"

Caelorna, Coral Tyrant

Riptide Turtle

Mistford River Turtle

Whenever this creature attacks, another target attacking non-Human creature can't be blocked this turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Glacial Wall

Shifting Wall

Defender (This creature can't attack.)
This creature enters with X +1/+1 counters on it.

Reverse the Polarity

Choose one —
• Counter all other spells.
• Switch each creature's power and toughness until end of turn.
• Creatures can't be blocked this turn.

Aegis Turtle

Floodgate

Defender
When this creature has flying, sacrifice it.
When this creature leaves the battlefield, it deals damage to each nonblue creature without flying equal to half the number of Islands you control, rounded down.

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Slagwurm Armor

Equipped creature gets +0/+6.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Twisted Image

Switch target creature's power and toughness until end of turn.
Draw a card.

Shell Shield

Kicker {1} (You may pay an additional {1} as you cast this spell.)
Target creature you control gets +0/+3 until end of turn. If this spell was kicked, that creature also gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Assassin Den

Defender (This creature can't attack.)
{3}{U}: Put a +1/+1 counter on target creature you control. It can't be blocked this turn. Activate only as a sorcery.

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Hover Barrier

Crenellated Wall

Defender (This creature can't attack.)
{T}: Target creature gets +0/+4 until end of turn.

Wall of Frost

Defender
Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step.

Switcheroo

Exchange control of two target creatures.

Necropolis

Defender (This creature can't attack.)
Exile a creature card from your graveyard: Put X +0/+1 counters on this creature, where X is the exiled card's mana value.

Quicksilver Wall

Defender (This creature can't attack.)
{4}: Return this creature to its owner's hand. Any player may activate this ability.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Island

Wall of Junk

Defender (This creature can't attack.)
When this creature blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Charix, the Raging Isle

Spells your opponents cast that target Charix cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Ambling Stormshell

Ward {2}
Whenever this creature attacks, put three stun counters on it and draw three cards. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you cast a Turtle spell, untap this creature.

Armored Whirl Turtle

Dragon Turtle

Flash
Drag Below — When this creature enters, tap it and up to one target creature an opponent controls. They don't untap during their controllers' next untap steps.

Canyon Crab

{1}{U}: This creature gets +2/-2 until end of turn.
At the beginning of your end step, if you haven't cast a spell from your hand this turn, draw a card, then discard a card.