Whenever a player casts a blue spell, you may gain 1 life.

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

Create a 0/3 blue Crab creature token. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Defender When Hightide Hermit enters the battlefield, you get {E}{E}{E}{E} (four energy counters). Pay {E}{E}: Hightide Hermit can attack this turn as though it didn't have defender.

{U}: Untap Horseshoe Crab.

{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.)

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

{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.

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Choose a creature type. Draw a card for each permanent you control of that type.

Draw two cards, then discard two cards. Untap up to three lands.

Equipped creature gets +3/+1. Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order. Equip {1}

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Look at the top three cards of your library. Put one of those cards into your hand, one into your graveyard, and one on the bottom of your library.

As Monastery Siege enters the battlefield, choose Khans or Dragons. • Khans — At the beginning of your draw step, draw an additional card, then discard a card. • Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

Look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

When Purple-Crystal Crab dies, draw a card.

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.

Enchant creature Enchanted creature has "{T}: This creature deals 1 damage to any target."

Enchant creature Enchanted creature can't be blocked. Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

{U}: Tap target green creature.

Equipped creature has skulk. (It can't be blocked by creatures with greater power.) Whenever equipped creature deals combat damage to a player, you may draw a card. If you do, discard a card. Equip {2}

Indestructible As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.) At the beginning of your upkeep, scry 1. {1}{U}: Target creature you control can't be blocked this turn.

Flying As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Castle Vantress enters the battlefield tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

Desert of the Mindful enters the battlefield tapped. {T}: Add {U}. Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

{T}, Sacrifice Escape Tunnel: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. {T}, Sacrifice Escape Tunnel: Target creature with power 2 or less can't be blocked this turn.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Halimar Depths enters the battlefield tapped. When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order. {T}: Add {U}.

Lonely Sandbar enters the battlefield tapped. {T}: Add {U}. Cycling {U} ({U}, Discard this card: Draw a card.)

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

When Obscura Storefront enters the battlefield, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Path of Ancestry enters the battlefield tapped. {T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Remote Isle enters the battlefield tapped. {T}: Add {U}. Cycling {2} ({2}, Discard this card: Draw a card.)

{T}: Add {C}. {4}, {T}: Target creature can't be blocked this turn.

Whenever you commit a crime, each opponent mills three cards. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

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

When Homarid Explorer enters the battlefield, target player mills four cards.

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.

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

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Coldsteel Heart enters the battlefield tapped. As Coldsteel Heart enters the battlefield, choose a color. {T}: Add one mana of the chosen color.

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Blue creature spells you cast cost {1} less to cast. Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

When Skittering Surveyor enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Sky Diamond enters the battlefield tapped. {T}: Add {U}.

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

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. When Solemn Simulacrum dies, you may draw a card.

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep. You draw a card at the beginning of the next turn's upkeep.

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

Flash This spell can't be countered. Whenever you cast a spell, choose up to one — • Return target spell you don't control to its owner's hand. • Return target nonland permanent to its owner's hand.

Enchant creature Enchanted creature loses all abilities and is a blue Fish with base power and toughness 0/1.

Enchant creature, land, or planeswalker Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

{1}{U}, {T}: Put target green creature on top of its owner's library.

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 Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Return target creature to its owner's hand. Untap up to two lands.

Return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control. Foretell {1}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Counter target spell unless its controller pays {1} for each blue permanent you control.

Until end of turn, target creature loses all abilities and becomes a blue Frog with base power and toughness 1/1.