Snow-Covered Mountain

Clarion Spirit

Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying.

Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Tundra Fumarole

Tundra Fumarole deals 4 damage to target creature or planeswalker. Add {C} for each {S} spent to cast this spell. Until end of turn, you don't lose this mana as steps and phases end. ({S} is mana from a snow source.)

Runeforge Champion

When this creature enters, you may search your library and/or graveyard for a Rune card, reveal it, and put it into your hand. If you search your library this way, shuffle.
You may pay {1} rather than pay the mana cost for Rune spells you cast.

Valor of the Worthy

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature leaves the battlefield, create a 1/1 white Spirit creature token with flying.

Beskir Shieldmate

When this creature dies, create a 1/1 white Human Warrior creature token.

Rune of Speed

Enchant permanent
When this Aura enters, draw a card.
As long as enchanted permanent is a creature, it gets +1/+0 and has haste.
As long as enchanted permanent is an Equipment, it has "Equipped creature gets +1/+0 and has haste."

Fearless Liberator

Boast — {2}{R}: Create a 2/1 red Dwarf Berserker creature token. (Activate only if this creature attacked this turn and only once each turn.)

Warhorn Blast

Creatures you control get +2/+1 until end of turn.
Foretell {2}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Alpine Meadow

({T}: Add {R} or {W}.)
This land enters tapped.

Usher of the Fallen

Boast — {1}{W}: Create a 1/1 white Human Warrior creature token. (Activate only if this creature attacked this turn and only once each turn.)

Frost Bite

Frost Bite deals 2 damage to target creature or planeswalker. If you control three or more snow permanents, it deals 3 damage instead.

Tuskeri Firewalker

Boast — {1}: Exile the top card of your library. You may play that card this turn. (Activate only if this creature attacked this turn and only once each turn.)

Snow-Covered Plains

Battershield Warrior

Boast — {1}{W}: Creatures you control get +1/+1 until end of turn. (Activate only if this creature attacked this turn and only once each turn.)

Warchanter Skald

Whenever this creature becomes tapped, if it's enchanted or equipped, create a 2/1 red Dwarf Berserker creature token.