Fog of Gnats

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 Scute Swarm instead.

Firefly

Flying
{R}: Firefly gets +1/+0 until end of turn.

Endless Cockroaches

When Endless Cockroaches dies, return it to its owner's hand.

Swamp

Duct Crawler

{1}{R}: Target creature can't block Duct Crawler this turn.

Fury Charm

Choose one —
• Destroy target artifact.
• Target creature gets +1/+1 and gains trample until end of turn.
• Remove two time counters from target permanent or suspended card.

Devouring Swarm

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

Plated Geopede

First strike
Landfall — Whenever a land you control enters, Plated Geopede gets +2/+2 until end of turn.

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.

Staff of the Flame Magus

Whenever you cast a red spell or a Mountain you control enters, you gain 1 life.

Caustic Caterpillar

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

Dragon's Claw

Whenever a player casts a red spell, you may gain 1 life.

Golgari Charm

Choose one —
• All creatures get -1/-1 until end of turn.
• Destroy target enchantment.
• Regenerate each creature you control.

Mazirek, Kraul Death Priest

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

Xira Arien

Flying
{B}{R}{G}, {T}: Target player draws a card.

Cavern Crawler

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
{R}: Cavern Crawler gets +1/-1 until end of turn.

Agitator Ant

At the beginning of your end step, each player may put two +1/+1 counters on a creature they control. Goad each creature that had counters put on it this way. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Umezawa's Charm

Choose one —
• Target creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.

Forest

Tunneling Geopede

Landfall — Whenever a land you control enters, Tunneling Geopede deals 1 damage to each opponent.

Beacon of Creation

Create a 1/1 green Insect creature token for each Forest you control. Shuffle Beacon of Creation into its owner's library.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Scute Mob

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

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.

Swarmyard

{T}: Add {C}.
{T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

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.)

Chaos Charm

Choose one —
• Destroy target Wall.
• Chaos Charm deals 1 damage to target creature.
• Target creature gains haste until end of turn.

Mountain

Carrion

As an additional cost to cast this spell, sacrifice a creature.
Create X 0/1 black Insect creature tokens, where X is the sacrificed creature's power.

Sol Ring

Saber Ants

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

Army Ants

{T}, Sacrifice a land: Destroy target land.

Darigaaz's Charm

Choose one —
• Return target creature card from your graveyard to your hand.
• Darigaaz's Charm deals 3 damage to any target.
• Target creature gets +3/+3 until end of turn.

Emerald Charm

Choose one —
• Untap target permanent.
• Destroy target non-Aura enchantment.
• Target creature loses flying until end of turn.

Giant Solifuge

({R/G} can be paid with either {R} or {G}.)
Trample; haste; shroud (This creature can't be the target of spells or abilities.)

Invader Parasite

Imprint — When Invader Parasite enters, exile target land.
Whenever a land an opponent controls with the same name as the exiled card enters, Invader Parasite deals 2 damage to that player.

Emerald Dragonfly

Flying
{G}{G}: Emerald Dragonfly gains first strike until end of turn.

Yavimaya Gnats

Wurm's Tooth

Whenever a player casts a green spell, you may gain 1 life.

Blightbeetle

Protection from green (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything green.)
Creatures your opponents control can't have +1/+1 counters put on them.

Staff of the Wild Magus

Whenever you cast a green spell or a Forest you control enters, you gain 1 life.

Giant Adephage

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

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Swarm of Bloodflies

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

Brood of Cockroaches

When Brood of Cockroaches is put into your graveyard from the battlefield, at the beginning of the next end step, you lose 1 life and return Brood of Cockroaches to your hand.

Staff of the Death Magus

Whenever you cast a black spell or a Swamp you control enters, you gain 1 life.

Gleancrawler

({B/G} can be paid with either {B} or {G}.)
Trample
At the beginning of your end step, return to your hand all creature cards in your graveyard that were put there from the battlefield this turn.

Robber Fly

Flying
Whenever Robber Fly becomes blocked, defending player discards all the cards in their hand, then draws that many cards.

Skin Shedder

Skin Invasion

Enchant creature
Enchanted creature attacks each combat if able.
When enchanted creature dies, return Skin Invasion to the battlefield transformed under your control.

Skin Invasion // Skin Shedder

Phyrexian Swarmlord

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
At the beginning of your upkeep, create a 1/1 green Phyrexian Insect creature token with infect for each poison counter your opponents have.

Rhonas's Monument

Green creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.

Skyclave Geopede

Trample
Landfall — Whenever a land you control enters, Skyclave Geopede gets +2/+2 until end of turn.

Kazandu Nectarpot

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

Gruul Charm

Choose one —
• Creatures without flying can't block this turn.
• Gain control of all permanents you own.
• Gruul Charm deals 3 damage to each creature with flying.

Ebony Charm

Choose one —
• Target opponent loses 1 life and you gain 1 life.
• Exile up to three target cards from a single graveyard.
• Target creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

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.)

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.)

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Fire Ants

{T}: Fire Ants deals 1 damage to each other creature without flying.

Jund Charm

Choose one —
• Exile target player's graveyard.
• Jund Charm deals 2 damage to each creature.
• Put two +1/+1 counters on target creature.

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.

Crash of Rhino Beetles

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

Heartstabber Mosquito

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Flying
When Heartstabber Mosquito enters, if it was kicked, destroy target creature.

Evolution Charm

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Return target creature card from your graveyard to your hand.
• Target creature gains flying until end of turn.

Mortician Beetle

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

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.