Kird Chieftain

This creature gets +1/+1 as long as you control a Forest.
{4}{G}: Target creature gets +2/+2 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Gorilla Shaman

{X}{X}{1}: Destroy target noncreature artifact with mana value X.

Gorilla Berserkers

Trample; rampage 2 (Whenever this creature becomes blocked, it gets +2/+2 until end of turn for each creature blocking it beyond the first.)
This creature can't be blocked except by three or more creatures.

Zodiac Monkey

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)

Descent into Avernus

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.

Kird Ape

This creature gets +1/+2 as long as you control a Forest.

Silverback Shaman

Trample
When this creature dies, draw a card.

Grunn, the Lonely King

Kicker {3} (You may pay an additional {3} as you cast this spell.)
If Grunn was kicked, it enters with five +1/+1 counters on it.
Whenever Grunn attacks alone, double its power and toughness until end of turn.

Simian Spirit Guide

Scrounging Bandar

This creature enters with two +1/+1 counters on it.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto another target creature.

Silverback Elder

Whenever you cast a creature spell, choose one —
• Destroy target artifact or enchantment.
• Look at the top five cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest on the bottom of your library in a random order.
• You gain 4 life.