Teacher's Pest

Menace (This creature can't be blocked except by two or more creatures.)
Whenever this creature attacks, you gain 1 life.
{B}{G}: Return this card from your graveyard to the battlefield tapped.

Ribtruss Roaster

Devour 1 (As this creature enters, you may sacrifice any number of creatures. This creature enters with that many +1/+1 counters on it.)
At the beginning of your end step, create a number of 1/1 black and green Pest creature tokens equal to the number of +1/+1 counters on this creature. They have "When this token dies, you gain 1 life."

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.

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 Friend

Create a 1/1 black and green Pest creature token with "Whenever this token attacks, you gain 1 life."

Lluwen, Exchange Student

Lluwen enters prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)
Exile a creature card from your graveyard: Lluwen becomes prepared. Activate only as a sorcery.

Lluwen, Exchange Student // Pest Friend

Bogwater Lumaret

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

Essence Warden

Whenever another creature enters, you gain 1 life.

Kazandu Nectarpot

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

Moldervine Reclamation

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

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.

Blech, Loafing Pest

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

Starscape Cleric

Offspring {2}{B} (You may pay an additional {2}{B} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
This creature can't block.
Whenever you gain life, each opponent loses 1 life.

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."

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.

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.

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.)

Turn Stones

For each opponent, you create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Eccentric Pestfinder

Trample
At the beginning of each end step, if you gained life this turn, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Eccentric Pestfinder // Turn Stones

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.

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.

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.

Moseo, Vein's New Dean

Flying
When Moseo enters, create a 1/1 black and green Pest creature token with "Whenever this token attacks, you gain 1 life."
Infusion — At the beginning of your end step, if you gained life this turn, return up to one target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this 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.)

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."

Dina, Soul Steeper

Whenever you gain life, each opponent loses 1 life.
{1}, Sacrifice another creature: Dina gets +X/+0 until end of turn, where X is the sacrificed creature's power.

Lisette, Dean of the Root

Whenever you gain life, you may pay {1}. If you do, put a +1/+1 counter on each creature you control and those creatures gain trample until end of turn.

Valentin, Dean of the Vein

Menace, lifelink
If a nontoken creature an opponent controls would die, exile it instead. When you do, you may pay {2}. If you do, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Valentin, Dean of the Vein // Lisette, Dean of the Root

Pest Mascot

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

Beledros Witherbloom

Flying
At the beginning of each upkeep, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
Pay 10 life: Untap all lands you control. Activate only once each turn.

Eumidian Terrabotanist

Pest Rescuer

At the beginning of each upkeep, if you don't control a Pest creature token, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
If you would gain life, you gain that much life plus 1 instead.

Haywire Mite

When this creature dies, you gain 2 life.
{G}, Sacrifice this creature: Exile target noncreature artifact or noncreature enchantment.

Ohran Frostfang

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

Twitching Doll

{T}: Add one mana of any color. Put a nest counter on this creature.
{T}, Sacrifice this creature: Create a 2/2 green Spider creature token with reach for each counter on this creature. Activate only as a sorcery.

Winding Constrictor

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.
If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.

Search for Blex

Look at the top five cards of your library. You may put any number of them into your hand and the rest into your graveyard. You lose 3 life for each card you put into your hand this way.

Blex, Vexing Pest

Other Pests, Bats, Insects, Snakes, and Spiders you control get +1/+1.
When Blex dies, you gain 4 life.