Blech, Loafing Pest

Whenever you gain life, put a +1/+1 counter on each Pest, Bat, Insect, Snake, and Spider you control.

Gorma, the Gullet

Lifelink
Whenever another creature you control dies, put a +1/+1 counter on Gorma.
Nontoken creatures you control enter with an additional +1/+1 counter on them for each creature that died under your control this turn.

Cauldron of Essence

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
{1}{B}{G}, {T}, Sacrifice a creature: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Feral Appetite

Attacking Pests you control get +1/+0 and have deathtouch.
{1}{G}: Exile target card from a graveyard. If a creature card is exiled this way, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Have

Grotesque Mutation

Target creature gets +3/+1 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Sol Ring

Meltstrider Eulogist

Whenever a creature you control with a +1/+1 counter on it dies, draw a card.

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Comforting Counsel

Whenever you gain life, put a growth counter on this enchantment.
As long as there are five or more growth counters on this enchantment, creatures you control get +3/+3.

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

Virulent Emissary

Deathtouch
Whenever another creature you control enters, you gain 1 life.

Springheart Nantuko

Bestow {1}{G}
Enchanted creature gets +1/+1.
Landfall — Whenever a land you control enters, you may pay {1}{G} if this permanent is attached to a creature you control. If you do, create a token that's a copy of that creature. If you didn't create a token this way, create a 1/1 green Insect creature token.

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}.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Command Tower

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

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Shopkeeper's Bane

Trample
Whenever this creature attacks, you gain 2 life.

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.)

Rust Scarab

Whenever this creature becomes blocked, you may destroy target artifact or enchantment defending player controls.

Send in the Pest

Each opponent discards a card. You create a 1/1 black and green Pest creature token with "Whenever this token attacks, you gain 1 life."

Golgari Rot Farm

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

Tend the Pests

As an additional cost to cast this spell, sacrifice a creature.
Create X 1/1 black and green Pest creature tokens with "When this token dies, you gain 1 life," where X is the sacrificed creature's power.

Fumulus, the Infestation

Flying, deathtouch
Whenever a player sacrifices a nontoken creature, create a 1/1 black Insect creature token with flying.
Whenever an Insect, Leech, Slug, or Worm you control attacks, defending player loses 1 life and you gain 1 life.

Necrosquito

Flying
This creature enters with two oil counters on it.
This creature gets +1/+1 for each oil counter on it.
Whenever another creature or artifact you control is put into a graveyard from the battlefield, put an oil counter on this creature.

Golgari Longlegs

Flesh Burrower

Deathtouch
Whenever this creature attacks, another target creature you control gains deathtouch until end of turn.

Shelob's Ambush

Target creature gets +1/+2 and gains deathtouch until end of turn. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Swamp

Eumidian Terrabotanist

Landfall — Whenever a land you control enters, you gain 1 life.

Kazandu Nectarpot

Insatiable Skittermaw

Menace (This creature can't be blocked except by two or more creatures.)
Void — At the beginning of your end step, if a nonland permanent left the battlefield this turn or a spell was warped this turn, put a +1/+1 counter on this creature.

Arachnogenesis

Create X 1/2 green Spider creature tokens with reach, where X is the number of creatures attacking you. Prevent all combat damage that would be dealt this turn by non-Spider creatures.

Reclaiming Vines

Destroy target artifact, enchantment, or land.

Perilous Shadow

{1}{B}: This creature gets +2/+2 until end of turn.

Enduring Tenacity

Whenever you gain life, target opponent loses that much life.
When Enduring Tenacity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Arasta of the Endless Web

Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.

Bogwater Lumaret

Whenever this creature or another creature you control enters, you gain 1 life.

Nantuko Cultivator

When this creature enters, you may discard any number of land cards. Put that many +1/+1 counters on this creature and draw that many cards.

Nessian Hornbeetle

At the beginning of combat on your turn, if you control another creature with power 4 or greater, put a +1/+1 counter on this creature.

Sedgemoor Witch

Menace
Ward—Pay 3 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 3 life.)
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Broodspinner

Reach
When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
{4}{B}{G}, {T}, Sacrifice this creature: Create a number of 1/1 black and green Insect creature tokens with flying equal to the number of card types among cards in your graveyard.

Duskshell Crawler

When this creature enters, put a +1/+1 counter on target creature.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Scute Swarm

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

Iridescent Hornbeetle

At the beginning of your end step, create a 1/1 green Insect creature token for each +1/+1 counter you've put on creatures under your control this turn.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Forest

Root Manipulation

Until end of turn, creatures you control get +2/+2 and gain menace and "Whenever this creature attacks, you gain 1 life." (A creature with menace can't be blocked except by two or more creatures.)

Spider Spawning

Create a 1/2 green Spider creature token with reach for each creature card in your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Plague Beetle

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Stream of Life

Hardened Scales

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.

Mornsong Aria

Players can't draw cards or gain life.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

Pest Mascot

Trample
Whenever you gain life, put a +1/+1 counter on this creature.

Hornet Nest

Defender (This creature can't attack.)
Whenever this creature 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.)

Kraul Whipcracker

Reach
When this creature enters, destroy target token an opponent controls.

Oran-Rief Recluse

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Reach (This creature can block creatures with flying.)
When this creature enters, if it was kicked, destroy target creature with flying.

Mazirek, Kraul Death Priest

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

Krotiq Nestguard

Defender
{2}{G}: This creature can attack this turn as though it didn't have defender.

Blight Mound

Attacking Pests you control get +1/+0 and have menace.
Whenever a nontoken creature you control dies, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Pest Summoning

Create two 1/1 black and green Pest creature tokens with "When this token dies, you gain 1 life."

Mammoth Spider

Reach (This creature can block creatures with flying.)

Moldgraf Millipede

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Murder

Pest Infestation

Destroy up to X target artifacts and/or enchantments. Create twice X 1/1 black and green Pest creature tokens with "When this token dies, you gain 1 life."