Phage the Untouchable

When Phage enters, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Hunted Lammasu

Flying
When this creature enters, target opponent creates a 4/4 black Horror creature token.

Hushwing Gryff

Flash
Flying
Creatures entering don't cause abilities to trigger.

Swamp

Changeling Titan

Changeling (This card is every creature type.)
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)

Phyrexian Dreadnought

Trample
When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Tocatli Honor Guard

Creatures entering don't cause abilities to trigger.

Plains

Spitebellows

When this creature leaves the battlefield, it deals 6 damage to target creature.
Evoke {1}{R}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Offalsnout

Flash
When this creature leaves the battlefield, exile target card from a graveyard.
Evoke {B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Ingot Chewer

When this creature enters, destroy target artifact.
Evoke {R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Tempting Wurm

When this creature enters, each opponent may put any number of artifact, creature, enchantment, and/or land cards from their hand onto the battlefield.

Cloudthresher

Flash
Reach
When this creature enters, it deals 2 damage to each creature with flying and each player.
Evoke {2}{G}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Hushbringer

Flying, lifelink
Creatures entering or dying don't cause abilities to trigger.

Eater of Days

Flying, trample
When this creature enters, you skip your next two turns.

Acererak the Archlich

When Acererak the Archlich enters, if you haven't completed Tomb of Annihilation, return Acererak the Archlich to its owner's hand and venture into the dungeon.
Whenever Acererak the Archlich attacks, for each opponent, you create a 2/2 black Zombie creature token unless that player sacrifices a creature of their choice.

Treacherous Pit-Dweller

When this creature enters from a graveyard, target opponent gains control of it.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Sandsteppe Citadel

This land enters tapped.
{T}: Add {W}, {B}, or {G}.

Forest

Boldwyr Heavyweights

Trample
When this creature enters, each opponent may search their library for a creature card and put it onto the battlefield. Then each player who searched their library this way shuffles.

Leveler

When this creature enters, exile all cards from your library.

Torpor Orb

Nova Chaser

Trample
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Demonlord of Ashmouth

Flying
When this creature enters, exile it unless you sacrifice another creature.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Hunted Horror

Trample
When this creature enters, target opponent creates two 3/3 green Centaur creature tokens with protection from black.