Necrotic Ooze

As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Adaptive Shimmerer

Flash
Adaptive Shimmerer enters with three +1/+1 counters on it.

Spinal Parasite

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)
Remove two +1/+1 counters from Spinal Parasite: Remove a counter from target permanent.

Nantuko Shade

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

Circuit Mender

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

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.

Plague Beetle

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

Foundry Hornet

Flying
When Foundry Hornet enters, if you control a creature with a +1/+1 counter on it, creatures your opponents control get -1/-1 until end of turn.

Skittering Heartstopper

{B}: Skittering Heartstopper gains deathtouch until end of turn.

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.)

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.

Pestilent Souleater

{B/P}: Pestilent Souleater gains infect until end of turn. ({B/P} can be paid with either {B} or 2 life. A creature with infect deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Nantuko Husk

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

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}.

Duskshell Crawler

When Duskshell Crawler 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.)

Fog of Gnats

Stirge

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

Loam Larva

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

Killer Bees

Flying
{G}: Killer Bees gets +1/+1 until end of turn.

Invasive Species

When Invasive Species enters, return another permanent you control to its owner's hand.

Ant Queen

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

Locust Swarm

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

Giant Ladybug

Reach
When Giant Ladybug enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Prakhata Pillar-Bug

{B}: Prakhata Pillar-Bug gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Zanikev Locust

Flying
Scavenge {2}{B}{B} ({2}{B}{B}, 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.)

Quarry Beetle

When Quarry Beetle enters, you may return target land card from your graveyard to the battlefield.

Nantuko Elder

Dross Hopper

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

Devouring Swarm

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

Agatha's Soul Cauldron

You may spend mana as though it were mana of any color to activate abilities of creatures you control.
Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron.
{T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.

Mortipede

{2}{G}: All creatures able to block Mortipede this turn do so.

Nantuko Calmer

{G}, {T}, Sacrifice Nantuko Calmer: Destroy target enchantment.
Threshold — Nantuko Calmer gets +1/+1 as long as seven or more cards are in your graveyard.

Mantis Engine

{2}: Mantis Engine gains flying until end of turn. (It can't be blocked except by creatures with flying or reach.)
{2}: Mantis Engine gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Kazandu Nectarpot

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

Moldgraf Millipede

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

Brain Maggot

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

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Thelonite Monk

{T}, Sacrifice a green creature: Target land becomes a Forest. (This effect lasts indefinitely.)

Rotfeaster Maggot

When Rotfeaster Maggot enters, exile target creature card from a graveyard. You gain life equal to that card's toughness.

Spinal Centipede

When Spinal Centipede dies, put a +1/+1 counter on target creature you control.

Canoptek Tomb Sentinel

Vigilance
Exile Cannon — When Canoptek Tomb Sentinel enters 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.)

Caustic Caterpillar

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

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.)

Kraul Foragers

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

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.

Phantom Nantuko

Trample
Phantom Nantuko enters with two +1/+1 counters on it.
If damage would be dealt to Phantom Nantuko, prevent that damage. Remove a +1/+1 counter from Phantom Nantuko.
{T}: Put a +1/+1 counter on Phantom Nantuko.

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.")

Durable Coilbug

{4}{B}: Return Durable Coilbug from your graveyard to your hand.

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.

Ironshell Beetle

When Ironshell Beetle enters, put a +1/+1 counter on target creature.

Stag Beetle

Stag Beetle enters with X +1/+1 counters on it, where X is the number of other creatures on the battlefield.

Battlefly Swarm

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

Hornet Queen

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

Nullmage Advocate

{T}: Return two target cards from an opponent's graveyard to their hand. Destroy target artifact or enchantment.

Yavimaya Gnats

Nantuko Cultivator

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

Rust Scarab

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