Ashaya, Soul of the Wild

Ashaya, Soul of the Wild's power and toughness are each equal to the number of lands you control.
Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)

Old-Growth Troll

Trample
When Old-Growth Troll dies, if it was a creature, return it to the battlefield. It's an Aura enchantment with enchant Forest you control and "Enchanted Forest has '{T}: Add {G}{G}' and '{1}, {T}, Sacrifice this land: Create a tapped 4/4 green Troll Warrior creature token with trample.'"

The Ringhart Crest

As The Ringhart Crest enters the battlefield, choose a creature type.
{T}: Add {G}. Spend this mana only to cast a creature spell of the chosen type or a legendary creature spell.

Kolvori, God of Kinship

As long as you control three or more legendary creatures, Kolvori gets +4/+2 and has vigilance.
{1}{G}, {T}: Look at the top six cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Kolvori, God of Kinship // The Ringhart Crest

Blizzard Brawl

Choose target creature you control and target creature you don't control. If you control three or more snow permanents, the creature you control gets +1/+0 and gains indestructible until end of turn. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

Werewolf Pack Leader

Pack tactics — Whenever Werewolf Pack Leader attacks, if you attacked with creatures with total power 6 or greater this combat, draw a card.
{3}{G}: Until end of turn, Werewolf Pack Leader has base power and toughness 5/3, gains trample, and isn't a Human.

The Tarrasque

The Tarrasque has haste and ward {10} as long as it was cast.
Whenever The Tarrasque attacks, it fights target creature defending player controls.

Blessing of Frost

Distribute X +1/+1 counters among any number of creatures you control, where X is the amount of {S} spent to cast this spell. Then draw a card for each creature you control with power 4 or greater.

Snow-Covered Forest

Lotus Cobra

Landfall — Whenever a land enters the battlefield under your control, add one mana of any color.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Echoing Equation

Choose target creature you control. Each other creature you control becomes a copy of it until end of turn, except those creatures aren't legendary.

Augmenter Pugilist

Trample
As long as you control eight or more lands, Augmenter Pugilist gets +5/+5.