Corridor Monitor

When Corridor Monitor enters the battlefield, untap target artifact or creature you control.

Caetus, Sea Tyrant of Segovia

Noncreature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
At the beginning of your end step, untap up to four target creatures.

Invasion of Segovia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Segovia enters the battlefield, create two 1/1 blue Kraken creature tokens with trample.

Invasion of Segovia // Caetus, Sea Tyrant of Segovia

Seat of the Synod

Bitter Chill

Enchant creature
When Bitter Chill enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
When Bitter Chill is put into a graveyard from the battlefield, you may pay {1}. If you do, scry 1, then draw a card.

Steelfin Whale

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Whenever an artifact enters the battlefield under your control, untap Steelfin Whale.

Frost Trickster

Flying
When Frost Trickster enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Trenzalore Clocktower

{T}: Add {U}. Put a time counter on Trenzalore Clocktower.
{1}{U}, {T}, Remove twelve time counters from Trenzalore Clocktower and exile it: Shuffle your graveyard and hand into your library, then draw seven cards. Activate only if you control a Time Lord.

Charmed Sleep

Enchant creature
When Charmed Sleep enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Icebreaker Kraken

This spell costs {1} less to cast for each snow land you control.
When Icebreaker Kraken enters the battlefield, artifacts and creatures target opponent controls don't untap during that player's next untap step.
Return three snow lands you control to their owner's hand: Return Icebreaker Kraken to its owner's hand.

Stop Cold

Flash
Enchant artifact or creature
When Stop Cold enters the battlefield, tap enchanted permanent.
Enchanted permanent loses all abilities and doesn't untap during its controller's untap step.

Scion of Stygia

Flash
Cone of Cold — When Scion of Stygia enters the battlefield, choose target creature an opponent controls, then roll a d20.
1—9 | Tap that creature.
10—20 | Tap that creature. It doesn't untap during its controller's next untap step.

Winter's Rest

Enchant creature
When Winter's Rest enters the battlefield, tap enchanted creature.
As long as you control another snow permanent, enchanted creature doesn't untap during its controller's untap step.

Sleep Paralysis

Enchant creature
When Sleep Paralysis enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Ray of Frost

Flash
Enchant creature
When Ray of Frost enters the battlefield, if enchanted creature is red, tap it.
As long as enchanted creature is red, it loses all abilities.
Enchanted creature doesn't untap during its controller's untap step.

Castaway's Despair

Enchant creature
When Castaway's Despair enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Guardian of Tazeem

Flying
Landfall — Whenever a land enters the battlefield under your control, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.

Singing Bell Strike

Enchant creature
When Singing Bell Strike enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature has "{6}: Untap this creature."

Breaching Hippocamp

Flash (You may cast this spell any time you could cast an instant.)
When Breaching Hippocamp enters the battlefield, untap another target creature you control.

Bewitching Leechcraft

Enchant creature
When Bewitching Leechcraft enters the battlefield, tap enchanted creature.
Enchanted creature has "If this creature would untap during your untap step, remove a +1/+1 counter from it instead. If you do, untap it." (Otherwise, it doesn't untap.)

Deceiver Exarch

Flash (You may cast this spell any time you could cast an instant.)
When Deceiver Exarch enters the battlefield, choose one —
• Untap target permanent you control.
• Tap target permanent an opponent controls.

Island

Abduction

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

Unquenchable Thirst

Enchant creature
When Unquenchable Thirst enters the battlefield, if you control a Desert or there is a Desert card in your graveyard, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Berg Strider

When Berg Strider enters the battlefield, tap target artifact or creature an opponent controls. If {S} was spent to cast this spell, that permanent doesn't untap during its controller's next untap step. ({S} is mana from a snow source.)

Icefall Regent

Flying
When Icefall Regent enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Icefall Regent.
Spells your opponents cast that target Icefall Regent cost {2} more to cast.

Merchant Raiders

Whenever Merchant Raiders or another Pirate enters the battlefield under your control, tap up to one target creature. That creature doesn't untap during its controller's untap step for as long as you control Merchant Raiders.

Sleeping Potion

Enchant creature
When Sleeping Potion enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
When enchanted creature becomes the target of a spell or ability, sacrifice Sleeping Potion.

Great Whale

When Great Whale enters the battlefield, untap up to seven lands.

Component Collector

If it's neither day nor night, it becomes day as Component Collector enters the battlefield.
Whenever day becomes night or night becomes day, you may tap or untap target nonland permanent.

Treachery

Enchant creature
When Treachery enters the battlefield, untap up to five lands.
You control enchanted creature.

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Mesmerizing Dose

Enchant creature
When Mesmerizing Dose enters the battlefield, tap enchanted creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Enchanted creature doesn't untap during its controller's untap step.

Snow-Covered Island

Malfunction

Enchant artifact or creature
When Malfunction enters the battlefield, tap enchanted permanent.
Enchanted permanent doesn't untap during its controller's untap step.

Captain of the Mists

Whenever another Human enters the battlefield under your control, untap Captain of the Mists.
{1}{U}, {T}: You may tap or untap target permanent.

Watertrap Weaver

When Watertrap Weaver enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Palinchron

Flying
When Palinchron enters the battlefield, untap up to seven lands.
{2}{U}{U}: Return Palinchron to its owner's hand.

Stunning Strike

Flash
Enchant creature
When Stunning Strike enters the battlefield, tap enchanted creature and remove it from combat.
As long as enchanted creature isn't legendary, it doesn't untap during its controller's untap step.

Fall from Favor

Enchant creature
When Fall from Favor enters the battlefield, tap enchanted creature and you become the monarch.
Enchanted creature doesn't untap during its controller's untap step unless that player is the monarch.

Tidebinder Mage

When Tidebinder Mage enters the battlefield, tap target red or green creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Tidebinder Mage.

Psychic Overload

Enchant permanent
When Psychic Overload enters the battlefield, tap enchanted permanent.
Enchanted permanent doesn't untap during its controller's untap step.
Enchanted permanent has "Discard two artifact cards: Untap this permanent."

Cloud of Faeries

Flying
When Cloud of Faeries enters the battlefield, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Janjeet Sentry

When Janjeet Sentry enters the battlefield, you get {E}{E} (two energy counters).
{T}, Pay {E}{E}: You may tap or untap target artifact or creature.

Claustrophobia

Enchant creature
When Claustrophobia enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Dramatic Accusation

Enchant creature
When Dramatic Accusation enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{U}{U}: Shuffle enchanted creature into its owner's library.

Thirst

Enchant creature
When Thirst enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of your upkeep, sacrifice Thirst unless you pay {U}.

Runner's Bane

Enchant creature with power 3 or less
When Runner's Bane enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Retreat to Coralhelm

Landfall — Whenever a land enters the battlefield under your control, choose one —
• You may tap or untap target creature.
• Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Tamiyo's Compleation

Flash
Enchant artifact, creature, or planeswalker
When Tamiyo's Compleation enters the battlefield, tap enchanted permanent. If it's an Equipment, unattach it.
Enchanted permanent loses all abilities and doesn't untap during its controller's untap step.

Junk Winder

Affinity for tokens (This spell costs {1} less to cast for each token you control.)
Whenever a token enters the battlefield under your control, tap target nonland permanent an opponent controls. It doesn't untap during its controller's next untap step.

Mystic Restraints

Flash
Enchant creature
When Mystic Restraints enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Tideforce Elemental

{U}, {T}: You may tap or untap another target creature.
Landfall — Whenever a land enters the battlefield under your control, you may untap Tideforce Elemental.

Capture Sphere

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

Fogwalker

Skulk (This creature can't be blocked by creatures with greater power.)
When Fogwalker enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.

Weakstone's Subjugation

Enchant artifact or creature
When Weakstone's Subjugation enters the battlefield, you may pay {3}. If you do, tap enchanted permanent.
Enchanted permanent doesn't untap during its controller's untap step.

Frost Titan

Whenever Frost Titan becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever Frost Titan enters the battlefield or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Trench Behemoth

Return a land you control to its owner's hand: Untap Trench Behemoth. It gains hexproof until end of turn.
Landfall — Whenever a land enters the battlefield under your control, target creature an opponent controls attacks during its controller's next combat phase if able.

Waterknot

Enchant creature
When Waterknot enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Breaching Leviathan

When Breaching Leviathan enters the battlefield, if you cast it from your hand, tap all nonblue creatures. Those creatures don't untap during their controllers' next untap steps.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

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.

Juvenile Mist Dragon

Flying
Confounding Clouds — When Juvenile Mist Dragon enters the battlefield, for each opponent, tap up to one target creature that player controls. Each of those creatures doesn't untap during its controller's next untap step.

Bind the Monster

Enchant creature
When Bind the Monster enters the battlefield, tap enchanted creature. It deals damage to you equal to its power.
Enchanted creature doesn't untap during its controller's untap step.

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

Iceberg Titan

Whenever Iceberg Titan attacks, you may tap or untap target artifact or creature.

Inverted Iceberg

When Inverted Iceberg enters the battlefield, mill a card, then draw a card. (To mill a card, put the top card of your library into your graveyard.)
Craft with artifact {4}{U}{U} ({4}{U}{U}, Exile this artifact, Exile another artifact you control or an artifact card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Inverted Iceberg // Iceberg Titan

Eternity Snare

Enchant creature
When Eternity Snare enters the battlefield, draw a card.
Enchanted creature doesn't untap during its controller's untap step.

Bubble Snare

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
Enchant creature
When Bubble Snare enters the battlefield, if it was kicked, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Sleep with the Fishes

Enchant creature
When Sleep with the Fishes enters the battlefield, tap enchanted creature and you create a 1/1 blue Fish creature token with "This creature can't be blocked."
Enchanted creature doesn't untap during its controller's untap step.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters the battlefield, untap all creatures.

Pestermite

Flash
Flying
When Pestermite enters the battlefield, you may tap or untap target permanent.

Castle Vantress

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

Hold for Questioning

Enchant creature or planeswalker
When Hold for Questioning enters the battlefield, tap enchanted permanent and investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Enchanted permanent doesn't untap during its controller's untap step and its activated abilities can't be activated.

Dungeon Geists

Flying
When Dungeon Geists enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Dungeon Geists.

Chillbringer

Flying
When Chillbringer enters the battlefield, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.

Tolaria

{T}: Add {U}.
{T}: Target creature loses banding and all "bands with other" abilities until end of turn. Activate only during any upkeep step.

Mesmerizing Benthid

When Mesmerizing Benthid enters the battlefield, create two 0/2 blue Illusion creature tokens with "Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step."
Mesmerizing Benthid has hexproof as long as you control an Illusion.

Frost Lynx

When Frost Lynx enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.