Archelos, Lagoon Mystic

As long as Archelos, Lagoon Mystic is tapped, other permanents enter the battlefield tapped.
As long as Archelos is untapped, other permanents enter the battlefield untapped.

Wandering Tombshell

Mistford River Turtle

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

Giant Turtle

Giant Turtle can't attack if it attacked during your last turn.

Meandering Towershell

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Meandering Towershell attacks, exile it. Return it to the battlefield under your control tapped and attacking at the beginning of the declare attackers step on your next turn.

Thriving Turtle

When Thriving Turtle enters the battlefield, you get {E}{E} (two energy counters).
Whenever Thriving Turtle attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Vanquisher's Banner

As Vanquisher's Banner enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Crystacean

Scuttlegator

Defender
{6}{G/U}{G/U}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)
As long as Scuttlegator has a +1/+1 counter on it, it can attack as though it didn't have defender.

Giant Tortoise

Giant Tortoise gets +0/+3 as long as it's untapped.

Vintara Snapper

Vintara Snapper has shroud as long as you control no untapped lands. (It can't be the target of spells or abilities.)

Sharktocrab

{2}{G}{U}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on Sharktocrab, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Jwari Scuttler

Purple-Crystal Crab

When Purple-Crystal Crab dies, draw a card.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Quandrix Cultivator

When Quandrix Cultivator enters the battlefield, you may search your library for a basic Forest or Island card, put it onto the battlefield, then shuffle.

Charix, the Raging Isle

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

Forest

Dragon Turtle

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

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Cold-Water Snapper

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

Horned Turtle

Sol Ring

Swamp

Calcite Snapper

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

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Silburlind Snapper

Silburlind Snapper can't attack unless you've cast a noncreature spell this turn.

Ancient Crab

Armored Whirl Turtle

Angler Turtle

Hexproof
Creatures your opponents control attack each combat if able.

Steelbane Hydra

Steelbane Hydra enters the battlefield with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from Steelbane Hydra: Destroy target artifact or enchantment.

Riptide Turtle

Shambleshark

Flash (You may cast this spell any time you could cast an instant.)
Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)