Grist, the Hunger Tide

As long as Grist, the Hunger Tide isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.

The Gitrog Monster

Deathtouch
At the beginning of your upkeep, sacrifice The Gitrog Monster unless you sacrifice a land.
You may play an additional land on each of your turns.
Whenever one or more land cards are put into your graveyard from anywhere, draw a card.

Exploration

You may play an additional land on each of your turns.

Scute Swarm

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

Kraul Harpooner

Reach
Undergrowth — When Kraul Harpooner enters the battlefield, choose up to one target creature you don't control with flying. Kraul Harpooner gets +X/+0 until end of turn, where X is the number of creature cards in your graveyard, then you may have Kraul Harpooner fight that creature.

Spring-Leaf Avenger

Ninjutsu {3}{G} ({3}{G}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Spring-Leaf Avenger deals combat damage to a player, return target permanent card from your graveyard to your hand.

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.

Nantuko Husk

Sacrifice a creature: Nantuko Husk gets +2/+2 until end of turn.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters the battlefield, choose a creature type.
Whenever another creature of the chosen type enters the battlefield under your control, put a +1/+1 counter on Bloodline Pretender.

Breach the Multiverse

Each player mills ten cards. For each player, choose a creature or planeswalker card in that player's graveyard. Put those cards onto the battlefield under your control. Then each creature you control becomes a Phyrexian in addition to its other types.

Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Kraul Whipcracker

Reach
When Kraul Whipcracker enters the battlefield, destroy target token an opponent controls.

Nantuko Elder

Hornet Queen

Flying, deathtouch
When Hornet Queen enters the battlefield, create four 1/1 green Insect creature tokens with flying and deathtouch.

Archdruid's Charm

Choose one —
• Search your library for a creature or land card and reveal it. Put it onto the battlefield tapped if it's a land card. Otherwise, put it into your hand. Then shuffle.
• Put a +1/+1 counter on target creature you control. It deals damage equal to its power to target creature you don't control.
• Exile target artifact or enchantment.

Giant Ankheg

Trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Other creatures you control have trample and ward {2}.

Insidious Roots

Creature tokens you control have "{T}: Add one mana of any color."
Whenever one or more creature cards leave your graveyard, create a 0/1 green Plant creature token, then put a +1/+1 counter on each Plant you control.

Mortician Beetle

Whenever a player sacrifices a creature, you may put a +1/+1 counter on Mortician Beetle.

Scute Mob

At the beginning of your upkeep, if you control five or more lands, put four +1/+1 counters on Scute Mob.

Bane of the Living

Morph {X}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Bane of the Living is turned face up, all creatures get -X/-X until end of turn.

Mazirek, Kraul Death Priest

Flying
Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.

Undergrowth Recon

At the beginning of your upkeep, return target land card from your graveyard to the battlefield tapped.

Crawling Infestation

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.

Izoni, Thousand-Eyed

Undergrowth — When Izoni, Thousand-Eyed enters the battlefield, create a 1/1 black and green Insect creature token for each creature card in your graveyard.
{B}{G}, Sacrifice another creature: You gain 1 life and draw a card.

Sol Ring

Hornet Nest

Defender (This creature can't attack.)
Whenever Hornet Nest is dealt damage, create that many 1/1 green Insect creature tokens with flying and deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Farseek

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

Beacon of Creation

Create a 1/1 green Insect creature token for each Forest you control. Shuffle Beacon of Creation into its owner's library.

Crash of Rhino Beetles

Trample
Crash of Rhino Beetles gets +10/+10 as long as you control ten or more lands.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters the battlefield, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Itlimoc, Cradle of the Sun

(Transforms from Growing Rites of Itlimoc.)
{T}: Add {G}.
{T}: Add {G} for each creature you control.

Growing Rites of Itlimoc

When Growing Rites of Itlimoc enters the battlefield, look at the top four cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
At the beginning of your end step, if you control four or more creatures, transform Growing Rites of Itlimoc.

Growing Rites of Itlimoc // Itlimoc, Cradle of the Sun

Cultivate

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.

Putrefy

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Arcane Signet

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

Zask, Skittering Swarmlord

You may play lands and cast Insect spells from your graveyard.
Whenever another Insect you control dies, put it on the bottom of its owner's library, then mill two cards. (Put the top two cards of your library into your graveyard.)
{1}{B/G}: Target Insect gets +1/+0 and gains deathtouch until end of turn. ({B/G} can be paid with either {B} or {G}.)

Old Rutstein

When Old Rutstein enters the battlefield or at the beginning of your upkeep, mill a card. If a land card is milled this way, create a Treasure token. If a creature card is milled this way, create a 1/1 green Insect creature token. If a noncreature, nonland card is milled this way, create a Blood token.

Ant Queen

{1}{G}: Create a 1/1 green Insect creature token.

Vraska, Golgari Queen

+2: You may sacrifice another permanent. If you do, you gain 1 life and draw a card.
−3: Destroy target nonland permanent with mana value 3 or less.
−9: You get an emblem with "Whenever a creature you control deals combat damage to a player, that player loses the game."

Squirming Emergence

Fathomless descent — Return to the battlefield target nonland permanent card in your graveyard with mana value less than or equal to the number of permanent cards in your graveyard.

Assassin's Trophy

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

Skylasher

Flash
This spell can't be countered.
Reach, protection from blue

Stinging Cave Crawler

Deathtouch
Descend 4 — Whenever Stinging Cave Crawler attacks, if there are four or more permanent cards in your graveyard, you draw a card and you lose 1 life.

Rampant Growth

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

Broodhatch Nantuko

Whenever Broodhatch Nantuko is dealt damage, you may create that many 1/1 green Insect creature tokens.
Morph {2}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Circuit Mender

When Circuit Mender enters the battlefield, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.

Crawling Sensation

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.

Ashnod's Altar

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Splendid Reclamation

Return all land cards from your graveyard to the battlefield tapped.

Eternal Witness

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Kazandu Nectarpot

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

Culling Ritual

Destroy each nonland permanent with mana value 2 or less. Add {B} or {G} for each permanent destroyed this way.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Giant Adephage

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

Living Hive

Trample
Whenever Living Hive deals combat damage to a player, create that many 1/1 green Insect creature tokens.

Blightbeetle

Protection from green (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything green.)
Creatures your opponents control can't have +1/+1 counters put on them.