Reinforcements

Put up to three target creature cards from your graveyard on top of your library.

Snow-Covered Island

Boreal Druid

Lat-Nam's Legacy

Shuffle a card from your hand into your library. If you do, draw two cards at the beginning of the next turn's upkeep.

Woolly Mammoths

Woolly Mammoths has trample as long as you control a snow land.

Snow-Covered Forest

Amrou Kithkin

Amrou Kithkin can't be blocked by creatures with power 3 or greater.

Deadly Insect

Shroud (This creature can't be the target of spells or abilities.)

Llanowar Elves

Awesome Presence

Enchant creature
Enchanted creature can't be blocked unless defending player pays {3} for each creature they control that's blocking it.

Boreal Centaur

{S}: Boreal Centaur gets +1/+1 until end of turn. Activate only once each turn. ({S} can be paid with one mana from a snow source.)

Unstable Mutation

Enchant creature
Enchanted creature gets +3/+3.
At the beginning of the upkeep of enchanted creature's controller, put a -1/-1 counter on that creature.

Into the North

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