Essence Symbiote

Whenever a creature you control mutates, put a +1/+1 counter on that creature and you gain 2 life.

Auspicious Starrix

Mutate {5}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, exile cards from the top of your library until you exile X permanent cards, where X is the number of times this creature has mutated. Put those permanent cards onto the battlefield.

Gemrazer

Mutate {1}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Reach, trample
Whenever this creature mutates, destroy target artifact or enchantment an opponent controls.

Migratory Greathorn

Mutate {2}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Llanowar Elves

Nissa, Who Shakes the World

Whenever you tap a Forest for mana, add an additional {G}.
+1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land.
−8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle.

End-Raze Forerunners

Vigilance, trample, haste
When End-Raze Forerunners enters, other creatures you control get +2/+2 and gain vigilance and trample until end of turn.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Paradise Druid

This creature has hexproof as long as it's untapped. (It can't be the target of spells or abilities your opponents control.)
{T}: Add one mana of any color.

Glowstone Recluse

Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Reach
Whenever this creature mutates, put two +1/+1 counters on it.

Forest

Barkhide Troll

Barkhide Troll enters with a +1/+1 counter on it.
{1}, Remove a +1/+1 counter from Barkhide Troll: Barkhide Troll gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Pelt Collector

Whenever another creature you control enters or dies, if that creature's power is greater than Pelt Collector's, put a +1/+1 counter on Pelt Collector.
As long as Pelt Collector has three or more +1/+1 counters on it, it has trample.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on it.

Yorvo, Lord of Garenbrig

Yorvo, Lord of Garenbrig enters with four +1/+1 counters on it.
Whenever another green creature you control enters, put a +1/+1 counter on Yorvo. Then if that creature's power is greater than Yorvo's power, put another +1/+1 counter on Yorvo.

Kogla, the Titan Ape

When Kogla, the Titan Ape enters, it fights up to one target creature you don't control.
Whenever Kogla attacks, destroy target artifact or enchantment defending player controls.
{1}{G}: Return target Human you control to its owner's hand. Kogla gains indestructible until end of turn.