Purple Worm

This spell costs {2} less to cast if a creature died this turn.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

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.

Duskdale Wurm

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Bellowing Tanglewurm

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Other green creatures you control have intimidate.

Forest

Green Slime

Flash
When Green Slime 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.)

Boneyard Wurm

Boneyard Wurm's power and toughness are each equal to the number of creature cards in your graveyard.

Necrotic Ooze

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

Ooze Garden

{1}{G}, Sacrifice a non-Ooze creature: Create an X/X green Ooze creature token, where X is the sacrificed creature's power. Activate only as a sorcery.

Gunk Slug

When Gunk Slug enters, create three Gunk token cards and shuffle them into target opponent's library. (Gunk is a colorless sorcery card with no mana cost that has cycling {4}.)

Arrogant Wurm

Trample
Madness {2}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Rocket-Powered Turbo Slug

Super haste (This may attack the turn before you cast it. (You may put this card from your hand onto the battlefield tapped and attacking during your declare attackers step. If you do, you lose the game at the beginning of your next turn's end step unless you pay this card's mana cost during that turn.))

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.

Johtull Wurm

Whenever Johtull Wurm becomes blocked, it gets -2/-1 until end of turn for each creature blocking it beyond the first.

Blitz Leech

Flash
When Blitz Leech enters, target creature an opponent controls gets -2/-2 until end of turn. Remove all counters from that creature.

Wormhole Serpent

{3}{U}: Target creature can't be blocked this turn.

Reef Worm

When Reef Worm dies, create a 3/3 blue Fish creature token with "When this creature dies, create a 6/6 blue Whale creature token with 'When this creature dies, create a 9/9 blue Kraken creature token.'"

Swamp Mosquito

Flying
Whenever Swamp Mosquito attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Brood of Cockroaches

When Brood of Cockroaches is put into your graveyard from the battlefield, at the beginning of the next end step, you lose 1 life and return Brood of Cockroaches to your hand.

Jade Leech

Green spells you cast cost {G} more to cast.

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.

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.

Simic Ragworm

Water Wurm

Water Wurm gets +0/+1 as long as an opponent controls an Island.

Giant Growth

Target creature gets +3/+3 until end of turn.

Feast of Worms

Destroy target land. If that land was legendary, its controller sacrifices another land of their choice.

Catacomb Slug

Endless Cockroaches

When Endless Cockroaches dies, return it to its owner's hand.

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.

Gluttonous Slug

Menace
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.)

Bookwurm

Trample
When Bookwurm enters, you gain 3 life and draw a card.
{2}{G}: Put Bookwurm from your graveyard into your library third from the top.

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.)

Giant Slug

{5}: At the beginning of your next upkeep, choose a basic land type. Giant Slug gains landwalk of the chosen type until the end of that turn. (It can't be blocked as long as defending player controls a land of that type.)

Carnage Wurm

Bloodthirst 3 (If an opponent was dealt damage this turn, this creature enters with three +1/+1 counters on it.)
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Molder Slug

At the beginning of each player's upkeep, that player sacrifices an artifact of their choice.

Insidious Bookworms

When Insidious Bookworms dies, you may pay {1}{B}. If you do, target player discards a card at random.

Wormfang Drake

Flying
When Wormfang Drake enters, sacrifice it unless you exile a creature you control other than Wormfang Drake.
When Wormfang Drake leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Advent of the Wurm

Create a 5/5 green Wurm creature token with trample.

Bloodhall Ooze

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.

Aeve, Progenitor Ooze

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 with a +1/+1 counter on it for each other Ooze you control.

Andradite Leech

Black spells you cast cost {B} more to cast.
{B}: Andradite Leech gets +1/+1 until end of turn.

Barbed-Back Wurm

{B}: Target green creature blocking Barbed-Back Wurm gets -1/-1 until end of turn.

Roaring Slagwurm

Whenever Roaring Slagwurm attacks, tap all artifacts.

Leechridden Swamp

({T}: Add {B}.)
Leechridden Swamp enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Ancient Ooze

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

Broodhunter Wurm

Primordial Ooze

Primordial Ooze attacks each combat if able.
At the beginning of your upkeep, put a +1/+1 counter on Primordial Ooze. Then you may pay {X}, where X is the number of +1/+1 counters on it. If you don't, tap Primordial Ooze and it deals X damage to you.

Slime Molding

Leeching Bite

Target creature gets +1/+1 until end of turn. Another target creature gets -1/-1 until end of turn.

Mwonvuli Ooze

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.

Leech Gauntlet

Lifelink
Equipped creature has lifelink.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Primal Cocoon

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.
When enchanted creature attacks or blocks, sacrifice Primal Cocoon.

Heartstabber Mosquito

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Flying
When Heartstabber Mosquito enters, if it was kicked, destroy target creature.

Battering Wurm

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Creatures with power less than Battering Wurm's power can't block it.

Dreadwurm

Landfall — Whenever a land you control enters, Dreadwurm gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Leeching Lurker

Lifelink
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Curse of Leeches

Enchant player
As this permanent transforms into Curse of Leeches, attach it to a player.
At the beginning of enchanted player's upkeep, they lose 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Curse of Leeches // Leeching Lurker

Mana Leech

You may choose not to untap Mana Leech during your untap step.
{T}: Tap target land. It doesn't untap during its controller's untap step for as long as Mana Leech remains tapped.

Mitotic Slime

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."

Mephitic Ooze

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.

Putrid Leech

Pay 2 life: Putrid Leech gets +2/+2 until end of turn. Activate only once each turn.

Harvest Wurm

When Harvest Wurm enters, sacrifice it unless you return a basic land card from your graveyard to your hand.

Spitting Slug

Whenever Spitting Slug blocks or becomes blocked, you may pay {1}{G}. If you do, Spitting Slug gains first strike until end of turn. Otherwise, each creature blocking or blocked by Spitting Slug gains first strike until end of turn.

Rain of Filth

Until end of turn, lands you control gain "Sacrifice this land: Add {B}."

Worm Harvest

Create a 1/1 black and green Worm creature token for each land card in your graveyard.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Wormfang Newt

When Wormfang Newt enters, exile a land you control.
When Wormfang Newt leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Slimefoot, the Stowaway

Whenever a Saproling you control dies, Slimefoot, the Stowaway deals 1 damage to each opponent and you gain 1 life.
{4}: Create a 1/1 green Saproling creature token.

Land Leeches

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.

Slimebind

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets -4/-0.

Carrion Wurm

Whenever Carrion Wurm attacks or blocks, any player may exile three cards from their graveyard. If a player does, Carrion Wurm assigns no combat damage this turn.

Engulfing Slagwurm

Whenever Engulfing Slagwurm blocks or becomes blocked by a creature, destroy that creature. You gain life equal to that creature's toughness.

Worms of the Earth

Players can't play lands.
Lands can't enter the battlefield.
At the beginning of each upkeep, any player may sacrifice two lands of their choice or have Worms of the Earth deal 5 damage to that player. If a player does either, destroy Worms of the Earth.

Ravaging Riftwurm

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
If Ravaging Riftwurm was kicked, it enters with three additional time counters on it.

Ravenous Slime

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.

Gravetiller Wurm

Trample
Morbid — Gravetiller Wurm enters with four +1/+1 counters on it if a creature died this turn.

Voracious Wurm

Voracious Wurm enters with X +1/+1 counters on it, where X is the amount of life you've gained this turn.

Crush of Wurms

Create three 6/6 green Wurm creature tokens.
Flashback {9}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Yule Ooze

At the beginning of your upkeep, destroy another nonland permanent chosen at random, then put a number of +1/+1 counters on Yule Ooze equal to that permanent's converted mana cost.
{R}{G}, Eat some food: Regenerate Yule Ooze.

Voidslime

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

Swamp

Corrosive Ooze

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

Leeching Licid

{B}, {T}: Leeching Licid loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {B} to end this effect.
At the beginning of the upkeep of enchanted creature's controller, Leeching Licid deals 1 damage to that player.

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.

Dogsnail Engine

Whenever you crank Dogsnail Engine, target player gains life equal to the greatest power among creatures you control.

Giant Cockroach

Gobbling Ooze

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

Mole Worms

You may choose not to untap Mole Worms during your untap step.
{T}: Tap target land. It doesn't untap during its controller's untap step for as long as Mole Worms remains tapped.

Filth

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
As long as Filth is in your graveyard and you control a Swamp, creatures you control have swampwalk.