Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy. Partner (You can have two commanders if both have partner.)

Choose a nonartifact, nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Whenever Cheering Fanatic attacks, choose a card name. Spells with the chosen name cost {1} less to cast this turn.

As Cloud Key enters the battlefield, choose artifact, creature, enchantment, instant, or sorcery. Spells you cast of the chosen type cost {1} less to cast.

Green spells you cast cost {1} less to cast.

Imprint — When Semblance Anvil enters the battlefield, you may exile a nonland card from your hand. Spells you cast that share a card type with the exiled card cost {2} less to cast.

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, the Collector enters the battlefield, choose a card type. Spells you cast of the chosen type cost {1} less to cast.

({T}: Add {B} or {G}.) As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

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

When Biogenic Ooze enters the battlefield, 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.

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

Evolve (Whenever a creature enters the battlefield under your control, 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 Experiment One: Regenerate Experiment One. (The next time this creature would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Each other non-Human creature you control enters the battlefield with an additional +1/+1 counter on it.

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

Commander creatures you own have "This creature enters the battlefield with an additional +1/+1 counter on it" and "Other creatures you control enter the battlefield with an additional +1/+1 counter on them."

Whenever a creature with power 5 or greater enters the battlefield under your control, you may put two +1/+1 counters on it.

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.

Whenever you cast your first instant or sorcery spell each turn, exile an instant or sorcery card at random from your graveyard. Then copy each card exiled with Arcane Bombardment. You may cast any number of the copies without paying their mana costs.

Whenever you cast an instant or sorcery spell from your hand, you may cast target card with the same name as that spell from your graveyard. (You still pay its costs.)

Whenever you cast an instant or sorcery spell that has the same name as a card in your graveyard, you may put a quest counter on Pyromancer Ascension. Whenever you cast an instant or sorcery spell while Pyromancer Ascension has two or more quest counters on it, you may copy that spell. You may choose new targets for the copy.

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.

Argoth, Sanctum of Nature enters the battlefield tapped unless you control a legendary green creature. {T}: Add {G}. {2}{G}{G}, {T}: Create a 2/2 green Bear creature token, then mill three cards. Activate only as a sorcery. (Melds with Titania, Voice of Gaea.)

({T}: Add {B} or {R}.) As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {R} or {G}.) Commercial District enters the battlefield tapped. When Commercial District enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

When Darigaaz's Caldera enters the battlefield, sacrifice it unless you return a non-Lair land you control to its owner's hand. {T}: Add {B}, {R}, or {G}.

({T}: Add {G}.)

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

Gruul Turf enters the battlefield tapped. When Gruul Turf enters the battlefield, return a land you control to its owner's hand. {T}: Add {R}{G}.

{T}: Add {C}. {1}, {T}: Add one mana of any color. {T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.

({T}: Add {R} or {G}.) Highland Forest enters the battlefield tapped.

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

({T}: Add {R}.)

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

Rakdos Carnarium enters the battlefield tapped. When Rakdos Carnarium enters the battlefield, return a land you control to its owner's hand. {T}: Add {B}{R}.

({T}: Add {B} or {R}.) Raucous Theater enters the battlefield tapped. When Raucous Theater enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

{T}: Add {C}. {1}{B}{R}, {T}: Each player discards a card. Activate only as a sorcery.

Savage Lands enters the battlefield tapped. {T}: Add {B}, {R}, or {G}.

({T}: Add {R} or {G}.) As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {B} or {R}.) Sulfurous Mire enters the battlefield tapped.

{T}: Add {C}. {2}, {T}: Look at the top card of your library. If it's an instant or sorcery card, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard. Activate only if you have exactly zero or seven cards in hand.

({T}: Add {B} or {G}.) Underground Mortuary enters the battlefield tapped. When Underground Mortuary enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

({T}: Add {B} or {G}.) Woodland Chasm enters the battlefield tapped.

Partner with Ukkima, Stalking Shadow (When this creature enters the battlefield, target player may put Ukkima into their hand from their library, then shuffle.) Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.

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

Whenever Bioplasm attacks, exile the top card of your library. If it's a creature card, Bioplasm gets +X/+Y until end of turn, where X is the exiled creature card's power and Y is its toughness.

As Brass Herald enters the battlefield, choose a creature type. When Brass Herald enters the battlefield, reveal the top four cards of your library. Put all creature cards of the chosen type revealed this way into your hand and the rest on the bottom of your library in any order. Creatures of the chosen type get +1/+1.

Indestructible Whenever Predator Ooze attacks, put a +1/+1 counter on it. Whenever a creature dealt damage by Predator Ooze this turn dies, put a +1/+1 counter on Predator Ooze.

Slurrk, All-Ingesting enters the battlefield 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.)

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

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

First strike {T}: Add an amount of {R} equal to the greatest power among creatures you control that entered the battlefield this turn. Partner (You can have two commanders if both have partner.)

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 creature'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 upkeep, you may mill two cards. (You may put the top two cards of your library into your graveyard.) Whenever one or more creature cards are put into your graveyard from anywhere during your turn, create a 1/1 green Insect creature token. This ability triggers only once each turn.

At the beginning of your upkeep, you may mill two cards. Whenever one or more land cards are put into your graveyard from anywhere for the first time each turn, create a 1/1 green Insect creature token.

As Door of Destinies enters the battlefield, choose a creature type. Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies. Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Create X X/X green Ooze creature tokens.

Changeling (This card is every creature type.) When Graveshifter enters the battlefield, you may return target creature card from your graveyard to your hand.

Reach Whenever another creature enters the battlefield under your control, you may pay {2}. When you do, that creature deals damage equal to its power to target creature. Partner (You can have two commanders if both have partner.)

As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

As Icon of Ancestry enters the battlefield, choose a creature type. Creatures you control of the chosen type get +1/+1. {3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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

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

At the beginning of your upkeep, put a +1/+1 counter on Necroplasm. At the beginning of your end step, destroy each creature with mana value equal to the number of +1/+1 counters on Necroplasm. 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.)

Create an X/X green Ooze creature token.

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith. At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

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 Uchuulon.

Changeling (This card is every creature type.)

As Vanquisher's Banner enters the battlefield, choose a creature type. Creatures you control of the chosen type get +1/+1. Whenever you cast a creature spell of the chosen type, draw a card.

Menace Whenever another creature dies during your turn, put a +1/+1 counter on Vogar, Necropolis Tyrant. When Vogar dies, draw a card for each +1/+1 counter on it.

{G}, Sacrifice another creature: Put a +1/+1 counter on Gobbling Ooze.

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."

Flash When Green Slime enters the battlefield, 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.)

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.

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead. {1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery. Cycling {2} ({2}, Discard this card: Draw a card.)

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Chaotic Goo enters the battlefield with three +1/+1 counters on it. At the beginning of your upkeep, you may flip a coin. If you win the flip, put a +1/+1 counter on Chaotic Goo. If you lose the flip, remove a +1/+1 counter from Chaotic Goo.

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

{1}{B}{R}: Note the name of target instant or sorcery card in your graveyard and put it onto the battlefield face down. It's a 3/3 creature with "Whenever this creature deals combat damage to a player, you may create a copy of the card with the noted name. You may cast the copy without paying its mana cost" and "If this creature would leave the battlefield, exile it instead of putting it anywhere else."

When Oran-Rief Ooze enters the battlefield, 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.

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

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

As Cover of Darkness enters the battlefield, choose a creature type. Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Equipped creature has first strike and gets +1/+0 for each instant and sorcery card in your graveyard. Whenever equipped creature deals combat damage to a player, you may cast an instant or sorcery spell from your hand with mana value less than or equal to that damage without paying its mana cost. Equip {3}

You may cast up to two instant and/or sorcery spells with total mana value 6 or less from your graveyard and/or hand without paying their mana costs. If those spells would be put into your graveyard, exile them instead. Exile Invoke Calamity.

Jeska, Thrice Reborn enters the battlefield with a loyalty counter on her for each time you've cast a commander from the command zone this game. 0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead. −X: Jeska, Thrice Reborn deals X damage to each of up to three targets. Jeska, Thrice Reborn can be your commander. Partner

Whenever a modified creature you control attacks, exile the top card of your library. You may play that card this turn. (Equipment, Auras you control, and counters are modifications.) Whenever you cast a spell from exile, put a +1/+1 counter on target creature you control.

Reach Whenever another permanent enters the battlefield under your control, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield. Partner (You can have two commanders if both have partner.)

Mephitic Ooze gets +1/+0 for each artifact you control. Whenever Mephitic Ooze deals combat damage to a creature, destroy that creature. The creature can't be regenerated.

When Minsc & Boo, Timeless Heroes enters the battlefield and at the beginning of your upkeep, you may create Boo, a legendary 1/1 red Hamster creature token with trample and haste. +1: Put three +1/+1 counters on up to one target creature with trample or haste. −2: Sacrifice a creature. When you do, Minsc & Boo, Timeless Heroes deals X damage to any target, where X is that creature's power. If the sacrificed creature was a Hamster, draw X cards. Minsc & Boo, Timeless Heroes can be your commander.

Cumulative upkeep {2} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay {2} for each age counter on it.) Mwonvuli Ooze's power and toughness are each equal to 1 plus twice the number of age counters on it.

{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.

Sacrifice a creature: Add {C}{C}.

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

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

This spell costs {X} less to cast, where X is the greatest power among creatures you control. Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures. {2}, {T}: Double target creature's power until end of turn.

Undergrowth Stadium enters the battlefield tapped unless you have two or more opponents. {T}: Add {B} or {G}.

({T}: Add {U} or {B}.) As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Destroy all creatures. They can't be regenerated.

When Goblin Engineer enters the battlefield, you may search your library for an artifact card, put it into your graveyard, then shuffle. {R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Ravenous Slime 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 Ravenous Slime.