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.

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.

Battlefly Swarm

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

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.)

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.

Pestilent Syphoner

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Kraul Raider

Menace (This creature can't be blocked except by two or more creatures.)

Gravepurge

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

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.)

Caustic Wasps

Flying
Whenever Caustic Wasps deals combat damage to a player, you may destroy target artifact that player controls.

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.

Vorapede

Vigilance, trample
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Yavimaya Gnats

Devouring Swarm

Flying
Sacrifice a creature: Devouring Swarm gets +1/+1 until end of turn.

Halo Scarab

{2}, Exile Halo Scarab from your graveyard: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters the battlefield, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Moldgraf Monstrosity

Trample
When Moldgraf Monstrosity dies, exile it, then return two creature cards at random from your graveyard to the battlefield.

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 Nessian Hornbeetle.

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.)

Plague Stinger

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Swarm of Bloodflies

Flying
Swarm of Bloodflies enters the battlefield with two +1/+1 counters on it.
Whenever another creature dies, put a +1/+1 counter on Swarm of Bloodflies.

Caustic Caterpillar

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

Dross Hopper

Sacrifice a creature: Dross Hopper gains flying until end of turn.

Nantuko Vigilante

Morph {1}{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.)
When Nantuko Vigilante is turned face up, destroy target artifact or enchantment.

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.

Stirge

Flying
Stirge can't block.
Blood Drain — {1}{B}, Pay 1 life, Sacrifice Stirge: Draw a card.

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}.)

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.

Kraul Foragers

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

Grave-Shell Scarab

{1}, Sacrifice Grave-Shell Scarab: Draw a card.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)

Mortal Combat

At the beginning of your upkeep, if twenty or more creature cards are in your graveyard, you win the game.

Forest

Locust Swarm

Flying
{G}: Regenerate Locust Swarm.
{G}: Untap Locust Swarm. Activate only once each turn.

Gigapede

Shroud (This creature can't be the target of spells or abilities.)
At the beginning of your upkeep, if Gigapede is in your graveyard, you may discard a card. If you do, return Gigapede to your hand.

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.

Footbottom Feast

Xantid Swarm

Flying
Whenever Xantid Swarm attacks, defending player can't cast spells this turn.

Nantuko Elder

Nantuko Shaman

When Nantuko Shaman enters the battlefield, if you control no tapped lands, draw a card.
Suspend 1—{2}{G}{G} (Rather than cast this card from your hand, you may pay {2}{G}{G} and exile it with a time counter on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Bone Harvest

Put any number of target creature cards from your graveyard on top of your library.
Draw a card at the beginning of the next turn's upkeep.

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.

Nantuko Tracer

When Nantuko Tracer enters the battlefield, you may put target card from a graveyard on the bottom of its owner's library.

Sol Ring

Saber Ants

Whenever Saber Ants is dealt damage, you may create that many 1/1 green Insect creature tokens.

Necrosquito

Flying
Necrosquito enters the battlefield with two oil counters on it.
Necrosquito 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 Necrosquito.

Carrion Grub

Carrion Grub gets +X/+0, where X is the greatest power among creature cards in your graveyard.
When Carrion Grub enters the battlefield, mill four cards. (Put the top four cards of your library into your graveyard.)

Atraxa's Skitterfang

Atraxa's Skitterfang enters the battlefield with three oil counters on it.
At the beginning of combat on your turn, you may remove an oil counter from Atraxa's Skitterfang. When you do, target creature you control gains your choice of flying, vigilance, deathtouch, or lifelink until end of turn.

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.

Coiling Woodworm

Coiling Woodworm's power is equal to the number of Forests on the battlefield.

Nantuko Cultivator

When Nantuko Cultivator enters the battlefield, you may discard any number of land cards. Put that many +1/+1 counters on Nantuko Cultivator and draw that many cards.

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters the battlefield, you may return target creature card from your graveyard to your hand.

Living Hive

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

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}.

Bilious Skulldweller

Deathtouch
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Swamp

Canoptek Tomb Sentinel

Vigilance
Exile Cannon — When Canoptek Tomb Sentinel enters the battlefield from a graveyard, exile up to one target nonland permanent.
Unearth {7} ({7}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Lattice-Blade Mantis

Lattice-Blade Mantis enters the battlefield with two oil counters on it.
Whenever Lattice-Blade Mantis attacks, you may remove an oil counter from it. If you do, untap it and it gets +1/+1 until end of turn.

Moldgraf Millipede

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

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.

Forever Young

Mind Maggots

When Mind Maggots enters the battlefield, discard any number of creature cards. For each card discarded this way, put two +1/+1 counters on Mind Maggots.

Carrion Beetles

{2}{B}, {T}: Exile up to three target cards from a single graveyard.

Nantuko Shade

{B}: Nantuko Shade gets +1/+1 until end of turn.

Nantuko Husk

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

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.