Crush of Tentacles

Surge {3}{U}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Return all nonland permanents to their owners' hands. If this spell's surge cost was paid, create an 8/8 blue Octopus creature token.

Castaway's Despair

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Mirror Match

Cast this spell only during the declare blockers step.
For each creature attacking you or a planeswalker you control, create a token that's a copy of that creature and that's blocking that creature. Exile those tokens at end of combat.

Island

Cephalid Illusionist

Whenever this creature becomes the target of a spell or ability, mill three cards.
{2}{U}, {T}: Prevent all combat damage that would be dealt to and dealt by target creature you control this turn.

Cephalid Broker

{T}: Target player draws two cards, then discards two cards.

Octavia, Living Thesis

This spell costs {8} less to cast if you have eight or more instant and/or sorcery cards in your graveyard.
Ward {8}
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature has base power and toughness 8/8 until end of turn.

Cephalid Pathmage

This creature can't be blocked.
{T}, Sacrifice this creature: Target creature can't be blocked this turn.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Eldrazi Scion

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.

Bubble Smuggler

Disguise {5}{U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
As this creature is turned face up, put four +1/+1 counters on it.

Godhunter Octopus

This creature can't attack unless defending player controls an enchantment or an enchanted permanent.

Shield Broker

When this creature enters, put a shield counter on target noncommander creature you don't control. You gain control of that creature for as long as it has a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Downpour

Cephalid Coliseum

{T}: Add {U}. This land deals 1 damage to you.
Threshold — {U}, {T}, Sacrifice this land: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

Octopus

Cephalid Inkshrouder

Discard a card: This creature gains shroud until end of turn and can't be blocked this turn. (A creature with shroud can't be the target of spells or abilities.)

Llawan, Cephalid Empress

When Llawan enters, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Cephalid Inkmage

When this creature enters, surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Threshold — This creature can't be blocked as long as there are seven or more cards in your graveyard.

Cephalid Snitch

Sacrifice this creature: Target creature loses protection from black until end of turn.

Aether Burst

Return up to X target creatures to their owners' hands, where X is one plus the number of cards named Aether Burst in all graveyards as you cast this spell.

Octoprophet

When this creature enters, 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.)

Aboshan, Cephalid Emperor

Tap an untapped Octopus you control: Tap target permanent.
{U}{U}{U}: Tap all creatures without flying.

Cephalid Constable

Whenever this creature deals combat damage to a player, return up to that many target permanents that player controls to their owner's hand.

Tidal Terror

Whenever this creature attacks, you may tap two other untapped creatures you control. If you do, this creature can't be blocked this turn.
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Chamber of Manipulation

Enchant land
Enchanted land has "{T}, Discard a card: Gain control of target creature until end of turn."

Touch of Invisibility

Target creature can't be blocked this turn.
Draw a card.

Choking Tethers

Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle this card, you may tap target creature.

Chronic Flooding

Enchant land
Whenever enchanted land becomes tapped, its controller mills three cards.

Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Mirror Mockery

Enchant creature
Whenever enchanted creature attacks, you may create a token that's a copy of that creature. Exile that token at end of combat.

Mercurial Transformation

Until end of turn, target nonland permanent loses all abilities and becomes your choice of a blue Frog creature with base power and toughness 1/1 or a blue Octopus creature with base power and toughness 4/4.

Dream Leash

Enchant permanent
You can't choose an untapped permanent as this spell's target as you cast it.
You control enchanted permanent.

Cephalid Shrine

Whenever a player casts a spell, counter that spell unless that player pays {X}, where X is the number of cards in all graveyards with the same name as the spell.

Domineering Will

Target player gains control of up to three target nonattacking creatures until end of turn. Untap those creatures. They block this turn if able.

Whelming Wave

Return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.

Cast Through Time

Instant and sorcery spells you control have rebound. (Exile the spell as it resolves if you cast it from your hand. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Keen Buccaneer

Vigilance
Exhaust — {1}{U}: Draw a card, then discard a card. Put a +1/+1 counter on this creature. (Activate each exhaust ability only once.)

Web of Inertia

At the beginning of combat on each opponent's turn, that player may exile a card from their graveyard. If the player doesn't, creatures they control can't attack you this turn.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Giant Octopus

Crab Umbra

Enchant creature
{2}{U}: Untap enchanted creature.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Cephalid Looter

{T}: Target player draws a card, then discards a card.

Curse of Inertia

Enchant player
Whenever a player attacks enchanted player with one or more creatures, that attacking player may tap or untap target permanent of their choice.

False Memories

Mill seven cards. At the beginning of the next end step, exile seven cards from your graveyard.

Moonring Island

({T}: Add {U}.)
This land enters tapped.
{U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.

Abduction

Enchant creature
When this Aura enters, untap enchanted creature.
You control enchanted creature.
When enchanted creature dies, return that card to the battlefield under its owner's control.

Lorthos, the Tidemaker

Whenever Lorthos attacks, you may pay {8}. If you do, tap up to eight target permanents. Those permanents don't untap during their controllers' next untap steps.

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Callous Oppressor

You may choose not to untap this creature during your untap step.
As this creature enters, an opponent chooses a creature type.
{T}: Gain control of target creature that isn't of the chosen type for as long as this creature remains tapped.

Abjure

As an additional cost to cast this spell, sacrifice a blue permanent.
Counter target spell.

Cephalid Scout

Flying
{2}{U}, Sacrifice a land: Draw a card.

Cephalid Aristocrat

Whenever this creature becomes the target of a spell or ability, mill two cards.

Chilling Grasp

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Madness {3}{U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Deluge

Cephalid Retainer

{U}{U}: Tap target creature without flying.

Cephalid Facetaker

This creature can't be blocked.
At the beginning of combat on your turn, you may have this creature become a copy of another target creature until end of turn, except it's 1/4 and has "This creature can't be blocked."

Cephalid Sage

Threshold — As long as seven or more cards are in your graveyard, this creature has "When this creature enters, draw three cards, then discard two cards."

Backstreet Bruiser

Defender
As long as there are two or more counters among creatures you control, this creature can attack as though it didn't have defender.

Think Tank

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Cephalid Vandal

At the beginning of your upkeep, put a shred counter on this creature. Then mill a card for each shred counter on this creature.

Apathy

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may discard a card at random. If the player does, untap that creature.

Aboshan's Desire

Enchant creature
Enchanted creature has flying.
Threshold — Enchanted creature has shroud as long as seven or more cards are in your graveyard. (It can't be the target of spells or abilities.)

Claustrophobia

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Adverse Conditions

Devoid (This card has no color.)
Tap up to two target creatures. Those creatures don't untap during their controller's next untap step. Create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}."

Grasp of Phantoms

Put target creature on top of its owner's library.
Flashback {7}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Betrayal

Enchant creature an opponent controls
Whenever enchanted creature becomes tapped, you draw a card.

Psychic Pickpocket

When this creature enters, it connives. When it connives this way, return up to one target nonland permanent to its owner's hand. (To have a creature connive, draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Omen Hawker

{T}: Add {C}{U}. Spend this mana only to activate abilities.

Sealock Monster

This creature can't attack unless defending player controls an Island.
{5}{U}{U}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, target land becomes an Island in addition to its other types.