Snow-Covered Island

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Arboreal Grazer

Reach
When Arboreal Grazer enters, you may put a land card from your hand onto the battlefield tapped.

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.

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.)

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

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.)

Pilfering Hawk

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

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters tapped.

Sculptor of Winter

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 Forest

Snow-Covered Mountain

Highland Forest

({T}: Add {R} or {G}.)
Highland Forest enters tapped.

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.

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.

Svella, Ice Shaper

{3}, {T}: Create a colorless snow artifact token named Icy Manalith with "{T}: Add one mana of any color."
{6}{R}{G}, {T}: Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.