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

You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

{T}: Add {C}{C}.

{1}{U}: Canyon Crab 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.

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.

Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Chromeshell Crab is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Flash

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.) {3}{U}{U}: Dreadlight Monstrosity can't be blocked this turn. Activate only if you own a card in exile.

Landfall — Whenever a land enters the battlefield under your control, target player mills three cards.

{U}: Untap Horseshoe Crab.

Whenever another snow permanent enters the battlefield under your control, you may have target player mill two cards.

Vigilance When Mirelurk Queen enters the battlefield, target player gets two rad counters. Whenever one or more nonland cards are milled, draw a card, then put a +1/+1 counter on Mirelurk Queen. This ability triggers only once each turn.

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.) Channel — {2}{U}, Discard Mirrorshell Crab: Counter target spell or ability unless its controller pays {3}.

When Purple-Crystal Crab dies, draw a card.

Alluring Eyes — {T}: Goad target creature an opponent controls. That player draws a card. You add {R}. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Vigilance When Riptide Crab dies, draw a card.

Ward {2} As Roaming Throne enters the battlefield, choose a creature type. Roaming Throne is the chosen type in addition to its other types. If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Landfall — Whenever a land enters the battlefield under your control, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Whenever Salvage Scuttler attacks, return an artifact you control to its owner's hand.

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.

Flash Vigilance When Scuttling Sentinel enters the battlefield, put a +1/+1 counter on another target creature you control. Until end of turn, that creature becomes a blue Crab in addition to its other types and gains hexproof. (It can't be the target of spells or abilities your opponents control.)

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.)

{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.

{2}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

{6}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.) As long as Skittering Crustacean is monstrous, it has hexproof. (It can't be the target of spells or abilities your opponents control.)

Bestow {5}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.) Whenever Thassa's Emissary or enchanted creature deals combat damage to a player, draw a card. Enchanted creature gets +3/+3.

Uchuulon's power is equal to the number of Crabs, Oozes, and/or Horrors you control. Horrific Symbiosis — At the beginning of your end step, exile up to one target creature card from an opponent's graveyard. If you do, create a token that's a copy of Uchuulon.