Realmbreaker, the Invasion Tree

{2}, {T}: Target opponent mills three cards. Put a land card from their graveyard onto the battlefield tapped under your control. It gains "If this land would leave the battlefield, exile it instead of putting it anywhere else."
{10}, {T}, Sacrifice Realmbreaker, the Invasion Tree: Search your library for any number of Praetor cards, put them onto the battlefield, then shuffle.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Pridemalkin

When Pridemalkin enters, put a +1/+1 counter on target creature you control.
Each creature you control with a +1/+1 counter on it has trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)

Have

Heroes' Bane

Heroes' Bane enters with four +1/+1 counters on it.
{2}{G}{G}: Put X +1/+1 counters on Heroes' Bane, where X is its power.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Rock Slide

Rock Slide deals X damage divided as you choose among any number of target attacking or blocking creatures without flying.

Herd Baloth

Whenever one or more +1/+1 counters are put on Herd Baloth, you may create a 4/4 green Beast creature token.

Forest

Savage Ventmaw

Flying
Whenever Savage Ventmaw attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Mountain

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Slime Molding

Dragon Tempest

Whenever a creature you control with flying enters, it gains haste until end of turn.
Whenever a Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.

Fractal Summoning

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it.

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Disintegrate

Disintegrate deals X damage to any target. If it's a creature, it can't be regenerated this turn, and if it would die this turn, exile it instead.

Grumgully, the Generous

Each other non-Human creature you control enters with an additional +1/+1 counter on it.

Stream of Life

Klauth, Unrivaled Ancient

Flying, haste
Whenever Klauth, Unrivaled Ancient attacks, add X mana in any combination of colors, where X is the total power of attacking creatures. Spend this mana only to cast spells. Until end of turn, you don't lose this mana as steps and phases end.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.
{R}: Scourge of Valkas gets +1/+0 until end of turn.

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters with an additional +1/+1 counter on it.

Thrakkus the Butcher

Trample
Whenever Thrakkus the Butcher attacks, double the power of each Dragon you control until end of turn.