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.)

Necropede

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Necropede dies, you may put a -1/-1 counter on target creature.

Duskshell Crawler

When Duskshell Crawler enters the battlefield, put a +1/+1 counter on target creature.
Each creature you control with a +1/+1 counter on it has trample.

Scute Mob

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

Loam Larva

When Loam Larva enters the battlefield, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Battlefly Swarm

Flying
{B}: Battlefly Swarm gains deathtouch until end of turn.

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}.)

Giant Adephage

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

Canoptek Scarab Swarm

Flying
Feeder Mandibles — When Canoptek Scarab Swarm enters the battlefield, exile target player's graveyard. For each artifact or land card exiled this way, create a 1/1 colorless Insect artifact creature token with flying.

Brain Maggot

When Brain Maggot enters the battlefield, target opponent reveals their hand and you choose a nonland card from it. Exile that card until Brain Maggot leaves the battlefield.

Crash of Rhino Beetles

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

Deadbridge Goliath

Scavenge {4}{G}{G} ({4}{G}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

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.

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.

Mazirek, Kraul Death Priest

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

Nantuko Elder

Mortician Beetle

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

Haywire Mite

When Haywire Mite dies, you gain 2 life.
{G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature 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}.

Kraul Foragers

Undergrowth — When Kraul Foragers enters the battlefield, you gain 1 life for each creature card in your graveyard.

Rust Scarab

Whenever Rust Scarab becomes blocked, you may destroy target artifact or enchantment defending player controls.

Caustic Caterpillar

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

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.