Iceberg Cancrix

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

Ghostly Flicker

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

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Rime Tender

{T}: Untap another target snow permanent.

String of Disappearances

Return target creature to its owner's hand. Then that creature's controller may pay {U}{U}. If the player does, they may copy this spell and may choose a new target for that copy.

Boreal Druid

Snow-Covered Forest

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Snow-Covered Island

Stream of Thought

Target player mills four cards. You shuffle up to four cards from your graveyard into your library.
Replicate {2}{U}{U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)

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.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Winter's Rest

Enchant creature
When Winter's Rest enters, tap enchanted creature.
As long as you control another snow permanent, enchanted creature doesn't untap during its controller's untap step.