Slurrk, All-Ingesting

Slurrk 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.)

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.

Aeve, Progenitor Ooze

Storm (When you cast this spell, copy it for each spell cast before it this turn. Copies become tokens.)
Aeve isn't legendary if it's a token.
Aeve enters with a +1/+1 counter on it for each other Ooze you control.

Experiment One

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.)
Remove two +1/+1 counters from this creature: Regenerate it. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Swamp

Consumptive Goo

{2}{B}{B}: Target creature gets -1/-1 until end of turn. Put a +1/+1 counter on this creature.

Gelatinous Cube

Engulf — When this creature enters, exile target non-Ooze creature an opponent controls until this creature leaves the battlefield.
Dissolve — {X}{B}: Put target creature card with mana value X exiled with this creature into its owner's graveyard.

Mountain

March of the World Ooze

Creatures you control have base power and toughness 6/6 and are Oozes in addition to their other types.
Whenever an opponent casts a spell, if it's not their turn, you create a 3/3 green Elephant creature token.

Garna, Bloodfist of Keld

Whenever another creature you control dies, draw a card if it was attacking. Otherwise, Garna deals 1 damage to each opponent.

Ooze Patrol

When this creature enters, mill two cards, then put a +1/+1 counter on this creature for each artifact and/or creature card in your graveyard. (To mill two cards, put the top two cards of your library into your graveyard.)

Deathreap Ritual

Morbid — At the beginning of each end step, if a creature died this turn, you may draw a card.

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.

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 this creature becomes monstrous, create a token that's a copy of this creature. (The token has no counters and isn't monstrous.)

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.

Twinferno

Choose one —
• When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Ravenous Slime

This creature can't be blocked by creatures with power 2 or less.
If a creature an opponent controls would die, instead exile it and put a number of +1/+1 counters equal to that creature's power on this creature.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Doom Weaver

Reach
Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Doom Weaver is paired with another creature, each of those creatures has "When this creature dies, draw cards equal to its power."

Expanding Ooze

{B}{G}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever this creature attacks, put a +1/+1 counter on target modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Slime Against Humanity

Create a 0/0 green Ooze creature token with trample. Put X +1/+1 counters on it, where X is two plus the total number of cards you own in exile and in your graveyard that are Oozes or are named Slime Against Humanity.
A deck can have any number of cards named Slime Against Humanity.

Acidic Slime

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

Hecteyes

When this creature enters, each opponent discards a card.

Clamavus

Proclamator Hailer — Each creature you control gets +1/+1 for each +1/+1 counter on it.

Necroplasm

At the beginning of your upkeep, put a +1/+1 counter on this creature.
At the beginning of your end step, destroy each creature with mana value equal to the number of +1/+1 counters on this creature.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Desperate Measures

Target creature gets +1/-1 until end of turn. When it dies under your control this turn, draw two cards.

Collector's Vault

{2}, {T}: Draw a card, then discard a card. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Triumph of Ferocity

At the beginning of your upkeep, draw a card if you control the creature with the greatest power or tied for the greatest power.

Abzan Beastmaster

At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness.

Gravitic Punch

Target creature you control deals damage equal to its power to target player.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Gluttonous Slime

Flash
Devour 1 (As this creature enters, you may sacrifice any number of creatures. It enters with that many +1/+1 counters on it.)

Oran-Rief Ooze

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

Command Tower

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

Temperamental Oozewagg

{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Modified creatures you control have trample. (Equipment, Auras you control, and counters are modifications.)

Scavenging Ooze

{G}: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on this creature and you gain 1 life.

Ziatora, the Incinerator

Flying
At the beginning of your end step, you may sacrifice another creature. When you do, Ziatora deals damage equal to that creature's power to any target and you create three Treasure tokens.

Peerless Recycling

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Return target permanent card from your graveyard to your hand. If the gift was promised, instead return two target permanent cards from your graveyard to your hand.

Forest

Bloodhall Ooze

At the beginning of your upkeep, if you control a black permanent, you may put a +1/+1 counter on this creature.
At the beginning of your upkeep, if you control a green permanent, you may put a +1/+1 counter on this creature.

Blitzball

{T}: Add one mana of any color.
GOOOOAAAALLL! — {T}, Sacrifice this artifact: Draw two cards. Activate only if an opponent was dealt combat damage by a legendary creature this turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Risky Shortcut

Draw two cards. Each player loses 2 life.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Green Slime

Flash
When this creature enters, counter target activated or triggered ability from an artifact or enchantment source. If a permanent's ability is countered this way, destroy that permanent.
Foretell {G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Increasing Vengeance

Copy target instant or sorcery spell you control. If this spell was cast from a graveyard, copy that spell twice instead. You may choose new targets for the copies.
Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mitotic Slime

When this creature dies, create two 2/2 green Ooze creature tokens. They have "When this token dies, create two 1/1 green Ooze creature tokens."

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Costly Plunder

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Terrian, World Tyrant

Inexorable Blob

Delirium — Whenever this creature attacks, if there are four or more card types among cards in your graveyard, create a 3/3 green Ooze creature token that's tapped and attacking.

Twisted Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.
Cycling {B}{R}{G} ({B}{R}{G}, Discard this card: Draw a card.)

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Printlifter Ooze

Deathtouch
Whenever this creature or another creature you control is turned face up, create a 0/0 green Ooze creature token with trample. The token enters with X +1/+1 counters on it, where X is the number of other creatures you control.
Disguise {3}{G}

Corrosive Ooze

Whenever this creature blocks or becomes blocked by an equipped creature, destroy all Equipment attached to that creature at end of combat.

Branching Evolution

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

Umori, the Collector

Companion — Each nonland card in your starting deck shares a card type. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
As Umori enters, choose a card type.
Spells you cast of the chosen type cost {1} less to cast.

Consuming Blob

Consuming Blob's power is equal to the number of card types among cards in your graveyard and its toughness is equal to that number plus 1.
At the beginning of your end step, create a green Ooze creature token with "This token's power is equal to the number of card types among cards in your graveyard and its toughness is equal to that number plus 1."

Biogenic Ooze

When this creature 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.

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.

Doublecast

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.