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.)

Lagonna-Band Trailblazer

Heroic — Whenever you cast a spell that targets Lagonna-Band Trailblazer, put a +1/+1 counter on Lagonna-Band Trailblazer.

Blossoming Sands

Blossoming Sands enters the battlefield tapped.
When Blossoming Sands enters the battlefield, you gain 1 life.
{T}: Add {G} or {W}.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Rosemane Centaur

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Vigilance

Snow-Covered Plains

Ecologist's Terrarium

When Ecologist's Terrarium enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, {T}, Sacrifice Ecologist's Terrarium: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Feat of Resistance

Put a +1/+1 counter on target creature you control. It gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)

Fertile Ground

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

Chronicler of Heroes

When Chronicler of Heroes enters the battlefield, draw a card if you control a creature with a +1/+1 counter on it.

Centaur Healer

When Centaur Healer enters the battlefield, you gain 3 life.

Snow-Covered Forest

Pheres-Band Tromper

Inspired — Whenever Pheres-Band Tromper becomes untapped, put a +1/+1 counter on it.

Forced Adaptation

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.

Pharika's Disciple

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)

Light the Way

Choose one —
• Put a +1/+1 counter on target creature or Vehicle. Untap it.
• Return target permanent you control to its owner's hand.

Ghor-Clan Savage

Bloodthirst 3 (If an opponent was dealt damage this turn, this creature enters the battlefield with three +1/+1 counters on it.)

Pheres-Band Thunderhoof

Heroic — Whenever you cast a spell that targets Pheres-Band Thunderhoof, put two +1/+1 counters on Pheres-Band Thunderhoof.

Captured by Lagacs

Enchant creature
Enchanted creature can't attack or block.
When Captured by Lagacs enters the battlefield, support 2. (Put a +1/+1 counter on each of up to two target creatures.)