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.

Kibo, Uktabi Prince

{T}: Each player creates a colorless artifact token named Banana with "{T}, Sacrifice this token: Add {R} or {G}. You gain 2 life."
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, put a +1/+1 counter on each creature you control that's an Ape or a Monkey.
Whenever Kibo attacks, defending player sacrifices an artifact of their choice.

Simian Spirit Guide

Simian Grunts

Flash
Echo {2}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Kird Ape

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

Simian Simulacrum

When this creature enters, put two +1/+1 counters on target creature you control.
Unearth {2}{G}{G} ({2}{G}{G}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Zodiac Monkey

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

Clockwork Percussionist

Haste
When this creature dies, exile the top card of your library. You may play it until the end of your next turn.

Uktabi Orangutan

When this creature enters, destroy target artifact.

Wave of Vitriol

Each player sacrifices all artifacts, enchantments, and nonbasic lands they control. For each land sacrificed this way, its controller may search their library for a basic land card and put it onto the battlefield tapped. Then each player who searched their library this way shuffles.

Elephant-Mandrill

Reach
When this creature enters, each player creates a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
At the beginning of combat on your turn, this creature gets +1/+1 until end of turn for each artifact your opponents control.

Marching Duodrone

Whenever this creature attacks, each player creates a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

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.

Yavimaya Steelcrusher

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
{1}, Sacrifice this creature: Destroy target artifact.

Silverback Shaman

Trample
When this creature dies, draw a card.

Gorilla Shaman

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

Gearbane Orangutan

Reach
When this creature enters, choose one —
• Destroy up to one target artifact.
• Sacrifice an artifact. If you do, put two +1/+1 counters on this creature.