Boreal Outrider

Whenever you cast a creature spell, if {S} of any of that spell's colors was spent to cast it, that creature enters the battlefield with an additional +1/+1 counter on it. ({S} is mana from a snow source.)

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.)

Blizzard Brawl

Choose target creature you control and target creature you don't control. If you control three or more snow permanents, the creature you control gets +1/+0 and gains indestructible until end of turn. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

Pilfering Hawk

Flying
{S}, {T}: Draw a card, then discard a card. ({S} can be paid with one mana from a snow source.)

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Gretchen Titchwillow

{2}{G}{U}: Draw a card. You may put a land card from your hand onto the battlefield.

Sculptor of Winter

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Inga and Esika

Creatures you control have vigilance and "{T}: Add one mana of any color. Spend this mana only to cast a creature spell."
Whenever you cast a creature spell, if three or more mana from creatures was spent to cast it, draw a card.

Spirit of the Aldergard

When Spirit of the Aldergard enters the battlefield, search your library for a snow land card, reveal it, put it into your hand, then shuffle.
Spirit of the Aldergard gets +1/+0 for each other snow permanent you control.

Ascendant Spirit

{S}{S}: Ascendant Spirit becomes a Spirit Warrior with base power and toughness 2/3.
{S}{S}{S}: If Ascendant Spirit is a Warrior, put a flying counter on it and it becomes a Spirit Warrior Angel with base power and toughness 4/4.
{S}{S}{S}{S}: If Ascendant Spirit is an Angel, put two +1/+1 counters on it and it gains "Whenever this creature deals combat damage to a player, draw a card."

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Into the North

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

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

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.)

Aqueous Form

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.)

Icebind Pillar

{S}, {T}: Tap target artifact or creature. ({S} can be paid with one mana from a snow source.)

Animist's Awakening

Reveal the top X cards of your library. Put all land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap those lands.

Kaldring, the Rimestaff

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

Jorn, God of Winter

Whenever Jorn attacks, untap each snow permanent you control.

Jorn, God of Winter // Kaldring, the Rimestaff

Rime Tender

{T}: Untap another target snow permanent.

Marit Lage's Slumber

Whenever Marit Lage's Slumber or another snow permanent enters the battlefield under your control, 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.

Overgrowth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}{G}.

Rampant Growth

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

Blessing of Frost

Distribute X +1/+1 counters among any number of creatures you control, where X is the amount of {S} spent to cast this spell. Then draw a card for each creature you control with power 4 or greater.

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Dead of Winter

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

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Rimewind Taskmage

{1}, {T}: You may tap or untap target permanent. Activate only if you control four or more snow permanents.

Glittering Frost

Enchant land
Enchanted land is snow.
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Abominable Treefolk

Trample
Abominable Treefolk's power and toughness are each equal to the number of snow permanents you control.
When Abominable Treefolk enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Frost Augur

{S}, {T}: Look at the top card of your library. If it's a snow card, you may reveal it and put it into your hand. ({S} can be paid with one mana from a snow source.)

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.