Withering Wisps

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Withering Wisps.
{B}: Withering Wisps deals 1 damage to each creature and each player. Activate no more times each turn than the number of snow Swamps you control.

Snowfall

Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an Island is tapped for mana, its controller may add an additional {U}. If that Island is snow, its controller may add an additional {U}{U} instead. Spend this mana only to pay cumulative upkeep costs.

Narfi, Betrayer King

Other snow and Zombie creatures you control get +1/+1.
{S}{S}{S}: Return Narfi, Betrayer King from your graveyard to the battlefield tapped. ({S} can be paid with one mana from a snow source.)

Iceberg Cancrix

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

Drift of the Dead

Defender (This creature can't attack.)
Drift of the Dead's power and toughness are each equal to the number of snow lands you control.

Rimebound Dead

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

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.)

Zombie Musher

Snow landwalk (This creature can't be blocked as long as defending player controls a snow land.)
{S}: Regenerate Zombie Musher. ({S} can be paid with one mana from a snow source.)

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.

Gangrenous Zombies

{T}, Sacrifice Gangrenous Zombies: Gangrenous Zombies deals 1 damage to each creature and each player. If you control a snow Swamp, Gangrenous Zombies deals 2 damage to each creature and each player instead.

Legions of Lim-Dûl

Snow swampwalk (This creature can't be blocked as long as defending player controls a snow Swamp.)

Balduvian Conjurer

{T}: Target snow land becomes a 2/2 creature until end of turn. It's still a land.

Snow Devil

Enchant creature
Enchanted creature has flying.
Enchanted creature has first strike as long as it's blocking and you control a snow land.

Priest of the Haunted Edge

{T}, Sacrifice Priest of the Haunted Edge: Target creature gets -X/-X until end of turn, where X is the number of snow lands you control. Activate only as a sorcery.

Icehide Golem

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

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Snow-Covered Swamp

Icebreaker Kraken

This spell costs {1} less to cast for each snow land you control.
When Icebreaker Kraken enters, 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.

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.

Snow-Covered Island

Snow Fortress

Defender (This creature can't attack.)
{1}: Snow Fortress gets +1/+0 until end of turn.
{1}: Snow Fortress gets +0/+1 until end of turn.
{3}: Snow Fortress deals 1 damage to target creature without flying that's attacking you.

Frostpeak Yeti

{1}{S}: Frostpeak Yeti can't be blocked this turn. ({S} can be paid with one mana from a snow source.)

Thermal Flux

Choose one —
• Target nonsnow permanent becomes snow until end of turn.
• Target snow permanent isn't snow until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Avalanche Caller

{2}: Target snow land you control becomes a 4/4 Elemental creature with hexproof and haste until end of turn. It's still a land. (A creature with hexproof can't be the target of spells or abilities your opponents control.)