Niv-Mizzet Reborn

Flying
When Niv-Mizzet enters, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Uchuulon

Uchuulon's power is equal to the number of Crabs, Oozes, and/or Horrors you control.
Horrific Symbiosis — At the beginning of your end step, exile up to one target creature card from an opponent's graveyard. If you do, create a token that's a copy of this creature.

Ochre Jelly

Trample
This creature enters with X +1/+1 counters on it.
Split — When this creature dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters with half that many +1/+1 counters on it, rounded down.

Impostor Syndrome

Whenever a nontoken creature you control deals combat damage to a player, create a token that's a copy of it, except it isn't legendary.

Biowaste Blob

Oozes you control get +1/+1.
At the beginning of your upkeep, if you control a commander, create a token that's a copy of this creature.

Sprouting Phytohydra

Defender (This creature can't attack.)
Whenever this creature is dealt damage, you may create a token that's a copy of this creature.

Life of the Party

First strike, trample, haste
Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of creatures you control.
When this creature enters, if it's not a token, each opponent creates a token that's a copy of it. The tokens are goaded for the rest of the game. (They attack each combat if able and attack a player other than you if able.)

Conclave Evangelist

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever this creature deals combat damage to a player, create a token that's a copy of this creature.

Mishra's Self-Replicator

Whenever you cast a historic spell, you may pay {1}. If you do, create a token that's a copy of this creature. (Artifacts, legendaries, and Sagas are historic.)

City of Death

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after VI.)
I — Create a Treasure token.
II, III, IV, V, VI — Create a token that's a copy of target non-Saga token you control.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of this creature instead.

Kinzu of the Bleak Coven

Flying
Whenever another nontoken creature you control dies, you may pay 2 life and exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and has toxic 1. (Players dealt combat damage by it also get a poison counter.)

Arcane Artisan

{2}{U}, {T}: Target player draws a card, then exiles a card from their hand. If a creature card is exiled this way, that player creates a token that's a copy of that card.
When this creature leaves the battlefield, exile all tokens created with it at the beginning of the next end step.

Nexus of Becoming

At the beginning of combat on your turn, draw a card. Then you may exile an artifact or creature card from your hand. If you do, create a token that's a copy of the exiled card, except it's a 3/3 Golem artifact creature in addition to its other types.

Wedding Ring

When this artifact enters, if it was cast, target opponent creates a token that's a copy of it.
Whenever an opponent who controls an artifact named Wedding Ring draws a card during their turn, you draw a card.
Whenever an opponent who controls an artifact named Wedding Ring gains life during their turn, you gain that much life.

Jace, Mirror Mage

Kicker {2}
When Jace enters, if Jace was kicked, create a token that's a copy of Jace, except it's not legendary and its starting loyalty is 1.
+1: Scry 2.
0: Draw a card and reveal it. Remove a number of loyalty counters equal to that card's mana value from Jace.

Giant Adephage

Trample
Whenever this creature deals combat damage to a player, create a token that's a copy of this creature.

Extravagant Replication

At the beginning of your upkeep, create a token that's a copy of another target nonland permanent you control.

Mirror-Sigil Sergeant

Trample
At the beginning of your upkeep, if you control a blue permanent, you may create a token that's a copy of this creature.

Battle for Bretagard

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 1/1 white Human Warrior creature token.
II — Create a 1/1 green Elf Warrior creature token.
III — Choose any number of artifact tokens and/or creature tokens you control with different names. For each of them, create a token that's a copy of it.

Watchful Radstag

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever this creature evolves, create a token that's a copy of it.

Followed Footsteps

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature.

Homunculus Horde

Whenever you draw your second card each turn, create a token that's a copy of this creature.

Bramble Sovereign

Whenever another nontoken creature enters, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.

Theoretical Duplication

Whenever a nontoken creature an opponent controls enters this turn, create a token that's a copy of that creature.

Spawnwrithe

Joo Dee, One of Many

{B}, {T}: Surveil 1. Create a token that's a copy of this creature, then sacrifice an artifact or creature. Activate only as a sorcery. (To surveil 1, look at the top card of your library. You may put it into your graveyard.)

Dreadfeast Demon

Flying
At the beginning of your end step, sacrifice a non-Demon creature. If you do, create a token that's a copy of this creature.

Polyraptor

Enrage — Whenever this creature is dealt damage, create a token that's a copy of this creature.

Compy Swarm

At the beginning of your end step, if a creature died this turn, create a tapped token that's a copy of this creature.

Bloodforged Battle-Axe

Equipped creature gets +2/+0.
Whenever equipped creature deals combat damage to a player, create a token that's a copy of this Equipment.
Equip {2}

Fractured Identity

Exile target nonland permanent. Each player other than its controller creates a token that's a copy of it.

Nightmare Shepherd

Flying
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Octomancer

Gift an Octopus (You may promise an opponent a gift as you cast this spell. If you do, when it enters, they create an 8/8 blue Octopus creature token.)
At the beginning of each end step, create a token that's a copy of target creature token that entered the battlefield this turn.

Springheart Nantuko

Bestow {1}{G}
Enchanted creature gets +1/+1.
Landfall — Whenever a land you control enters, you may pay {1}{G} if this permanent is attached to a creature you control. If you do, create a token that's a copy of that creature. If you didn't create a token this way, create a 1/1 green Insect creature token.

Brenard, Ginger Sculptor

Each creature you control that's a Food or a Golem gets +2/+2 and has trample.
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's a 1/1 Food Golem artifact creature in addition to its other types and it has "{2}, {T}, Sacrifice this token: You gain 3 life."

Hazel of the Rootbloom

{T}, Pay 2 life, Tap X untapped tokens you control: Add X mana in any combination of colors.
At the beginning of your end step, create a token that's a copy of target token you control. If that token is a Squirrel, instead create two tokens that are copies of it.

Mirror Mockery

Enchant creature
Whenever enchanted creature attacks, you may create a token that's a copy of that creature. Exile that token at end of combat.