Splitting Slime

{4}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Splitting Slime becomes monstrous, create a token that's a copy of Splitting Slime. (The token has no counters and isn't monstrous.)

Oran-Rief Ooze

When Oran-Rief Ooze enters, put a +1/+1 counter on target creature you control.
Whenever Oran-Rief Ooze attacks, put a +1/+1 counter on each attacking creature with a +1/+1 counter on it.

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Bred for the Hunt

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

Gigantoplasm

You may have Gigantoplasm enter as a copy of any creature on the battlefield, except it has "{X}: This creature has base power and toughness X/X."

Cryptoplasm

At the beginning of your upkeep, you may have Cryptoplasm become a copy of another target creature, except it has this ability.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Temple of Mystery

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {U}.

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.

Vorel of the Hull Clade

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Manaplasm

Whenever you cast a spell, Manaplasm gets +X/+X until end of turn, where X is that spell's mana value.

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Biomantic Mastery

Draw a card for each creature target player controls, then draw a card for each creature another target player controls.

Novijen, Heart of Progress

{T}: Add {C}.
{G}{U}, {T}: Put a +1/+1 counter on each creature that entered this turn.

Dimir Doppelganger

{1}{U}{B}: Exile target creature card from a graveyard. Dimir Doppelganger becomes a copy of that card, except it has this ability.

Followed Footsteps

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

Ochre Jelly

Trample
Ochre Jelly enters with X +1/+1 counters on it.
Split — When Ochre Jelly 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.

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Gutter Grime

Whenever a nontoken creature you control dies, put a slime counter on Gutter Grime, then create a green Ooze creature token with "This creature's power and toughness are each equal to the number of slime counters on Gutter Grime."

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Island

Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Predator Ooze

Indestructible (Damage and effects that say "destroy" don't destroy this creature.)
Whenever this creature attacks, put a +1/+1 counter on it.
Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature.

Miming Slime

Create an X/X green Ooze creature token, where X is the greatest power among creatures you control.

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Cultivate

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Temple of Malady

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {G}.

Llanowar Reborn

Llanowar Reborn enters tapped.
{T}: Add {G}.
Graft 1 (This land enters with a +1/+1 counter on it. Whenever a creature enters, you may move a +1/+1 counter from this land onto it.)

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Gelatinous Genesis

Ancient Ooze

Ancient Ooze's power and toughness are each equal to the total mana value of other creatures you control.

Slurrk, All-Ingesting

Slurrk, All-Ingesting enters with five +1/+1 counters on it.
Whenever Slurrk or another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Necrotic Ooze

As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Experiment Kraj

Experiment Kraj has all activated abilities of each other creature with a +1/+1 counter on it.
{T}: Put a +1/+1 counter on target creature.

Necroblossom Snarl

As Necroblossom Snarl enters, you may reveal a Swamp or Forest card from your hand. If you don't, Necroblossom Snarl enters tapped.
{T}: Add {B} or {G}.

Golgari Signet

Mirror Image

You may have Mirror Image enter as a copy of a creature you control.

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Corpsejack Menace

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on it instead.

Thornwood Falls

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {U}.

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Sol Ring

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Progenitor Mimic

You may have Progenitor Mimic enter as a copy of any creature on the battlefield, except it has "At the beginning of your upkeep, if this creature isn't a token, create a token that's a copy of this creature."

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Extravagant Replication

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

Arcane Signet

Biogenic Ooze

When Biogenic Ooze enters, create a 2/2 green Ooze creature token.
At the beginning of your end step, put a +1/+1 counter on each Ooze you control.
{1}{G}{G}{G}: Create a 2/2 green Ooze creature token.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Urban Evolution

Draw three cards. You may play an additional land this turn.

Simic Signet

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

Forest

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

The Mimeoplasm

As The Mimeoplasm enters, you may exile two creature cards from graveyards. If you do, it enters as a copy of one of those cards with a number of additional +1/+1 counters on it equal to the power of the other card.

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Swamp

Ooze Flux

{1}{G}, Remove one or more +1/+1 counters from among creatures you control: Create an X/X green Ooze creature token, where X is the number of +1/+1 counters removed this way.

Death's Presence

Whenever a creature you control dies, put X +1/+1 counters on target creature you control, where X is the power of the creature that died.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Soul's Majesty

Draw cards equal to the power of target creature you control.

Master Biomancer

Each other creature you control enters with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Counterspell

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 Biowaste Blob.