Marit Lage's Slumber

Whenever Marit Lage's Slumber or another snow permanent you control enters, scry 1.
At the beginning of your upkeep, if you control ten or more snow permanents, sacrifice Marit Lage's Slumber. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Arcum's Astrolabe

({S} can be paid with one mana from a snow source.)
When Arcum's Astrolabe enters, draw a card.
{1}, {T}: Add one mana of any color.

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Faerie Artisans

Flying
Whenever a nontoken creature an opponent controls enters, create a token that's a copy of that creature except it's an artifact in addition to its other types. Then exile all other tokens created with Faerie Artisans.

Springbloom Druid

When Springbloom Druid enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Flood of Tears

Return all nonland permanents to their owners' hands. If you return four or more nontoken permanents you control this way, you may put a permanent card from your hand onto the battlefield.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Thornwood Falls

Thornwood Falls enters tapped.
When Thornwood Falls enters, you gain 1 life.
{T}: Add {G} or {U}.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Wavesifter

Flying
When Wavesifter enters, investigate twice. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Evoke {G}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Lotleth Giant

Undergrowth — When Lotleth Giant enters, it deals 1 damage to target opponent for each creature card in your graveyard.

Snow-Covered Forest

Risen Reef

Whenever Risen Reef or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Into the Roil

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Malakir Mire

Malakir Mire enters tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

Awakened Skyclave

Vigilance, haste
As long as Awakened Skyclave is on the battlefield, it's a land in addition to its other types.
{T}: Add one mana of any color.

Invasion of Zendikar

(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 Zendikar enters, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Invasion of Zendikar // Awakened Skyclave

Yarok, the Desecrated

Deathtouch, lifelink
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Reclamation Sage

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Faerie Seer

Dinrova Horror

When Dinrova Horror enters, return target permanent to its owner's hand, then that player discards a card.

Sunscorched Desert

When Sunscorched Desert enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Pelakka Wurm

Trample
When Pelakka Wurm enters, you gain 7 life.
When Pelakka Wurm dies, draw a card.

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Snow-Covered Swamp

Temple of Malady

Temple of Malady enters tapped.
When Temple of Malady enters, scry 1.
{T}: Add {B} or {G}.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Kiora, Behemoth Beckoner

Whenever a creature you control with power 4 or greater enters, draw a card.
−1: Untap target permanent.

Golgari Signet

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Dead of Winter

All nonsnow creatures get -X/-X until end of turn, where X is the number of snow permanents you control.

Into the North

Search your library for a snow land card, put it onto the battlefield tapped, then shuffle.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Atris, Oracle of Half-Truths

Menace
When Atris, Oracle of Half-Truths enters, target opponent looks at the top three cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Treacherous Blessing

When Treacherous Blessing enters, draw three cards.
Whenever you cast a spell, you lose 1 life.
When Treacherous Blessing becomes the target of a spell or ability, sacrifice it.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Frost Marsh

Frost Marsh enters tapped.
{T}: Add {U} or {B}.

Simic Signet

Moritte of the Frost

Changeling (This card is every creature type.)
You may have Moritte of the Frost enter as a copy of a permanent you control, except it's legendary and snow in addition to its other types and, if it's a creature, it enters with two additional +1/+1 counters on it and has changeling.

Snow-Covered Island

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Woodland Chasm

({T}: Add {B} or {G}.)
Woodland Chasm enters tapped.

Evolving Wilds

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

Foundation Breaker

When Foundation Breaker enters, you may destroy target artifact or enchantment.
Evoke {1}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

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.

Torgaar, Famine Incarnate

As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed this way.
When Torgaar, Famine Incarnate enters, up to one target player's life total becomes half their starting life total, rounded down.

Aether Channeler

When Aether Channeler enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Crumbling Vestige

Crumbling Vestige enters tapped.
When Crumbling Vestige enters, add one mana of any color.
{T}: Add {C}. ({C} represents colorless mana.)

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Sphinx of Uthuun

Flying
When Sphinx of Uthuun enters, reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Primordial Mist

At the beginning of your end step, you may manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Exile a face-down permanent you control face up: You may play that card this turn. (You still pay its costs. Timing rules still apply.)

Jungle Hollow

Jungle Hollow enters tapped.
When Jungle Hollow enters, you gain 1 life.
{T}: Add {B} or {G}.

Temple of Mystery

Temple of Mystery enters tapped.
When Temple of Mystery enters, scry 1.
{T}: Add {G} or {U}.

Dismal Backwater

Dismal Backwater enters tapped.
When Dismal Backwater enters, you gain 1 life.
{T}: Add {U} or {B}.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Zendikar's Roil

Landfall — Whenever a land you control enters, create a 2/2 green Elemental creature token.

Hierophant's Chalice

When Hierophant's Chalice enters, target opponent loses 1 life and you gain 1 life.
{T}: Add {C}.

Ineffable Blessing

As Ineffable Blessing enters, choose Flavorful or Bland.
• Flavorful — Whenever a creature with flavor text enters under your control, draw a card.
• Bland — Whenever a creature without flavor text enters under your control, draw a card.

Blood on the Snow

Choose one —
• Destroy all creatures.
• Destroy all planeswalkers.
Then return a creature or planeswalker card with mana value X or less from your graveyard to the battlefield, where X is the amount of {S} spent to cast this spell. ({S} is mana from a snow source.)

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Kaldring, the Rimestaff

{T}: You may play target snow permanent card from your graveyard this turn. If you do, it enters tapped.

Jorn, God of Winter

Whenever Jorn attacks, untap each snow permanent you control.

Jorn, God of Winter // Kaldring, the Rimestaff

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters tapped.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Naru Meha, Master Wizard

Flash
When Naru Meha, Master Wizard enters, copy target instant or sorcery spell you control. You may choose new targets for the copy.
Other Wizards you control get +1/+1.

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Peregrine Drake

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

Izoni, Thousand-Eyed

Undergrowth — When Izoni, Thousand-Eyed enters, create a 1/1 black and green Insect creature token for each creature card in your graveyard.
{B}{G}, Sacrifice another creature: You gain 1 life and draw a card.

Khalni Garden

Khalni Garden enters tapped.
When Khalni Garden enters, create a 0/1 green Plant creature token.
{T}: Add {G}.

Satyr Wayfinder

When Satyr Wayfinder enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Icehide Golem

({S} can be paid with one mana from a snow source.)

Verdant Haven

Enchant land
When Verdant Haven enters, you gain 2 life.
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, Temur Sabertooth gains indestructible until end of turn.

Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Blizzard Strix

Flash
Flying
When Blizzard Strix enters, if you control another snow permanent, exile target permanent other than Blizzard Strix. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Cleanup Crew

When Cleanup Crew enters, choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.
• You gain 4 life.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Wild Pair

Whenever a creature enters, if you cast it from your hand, you may search your library for a creature card with the same total power and toughness, put it onto the battlefield, then shuffle.

Mosswort Bridge

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Mosswort Bridge enters tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

Iceberg Cancrix

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

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.