Swift Spinner

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)

Golgari Signet

Mutant's Prey

Target creature you control with a +1/+1 counter on it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Compelled Duel

Target creature gets +3/+3 until end of turn and must be blocked this turn if able.

Hunter's Mark

This spell costs {3} less to cast if it targets a blue permanent you don't control.
This spell can't be countered.
Target creature you control gets +1/+1 until end of turn. Then it deals damage equal to its power to target creature or planeswalker you don't control.

Thran Dynamo

Shelob, Child of Ungoliant

Deathtouch, ward {2}
Other Spiders you control have deathtouch and ward {2}.
Whenever another creature dealt damage this turn by a Spider you controlled dies, create a token that's a copy of that creature, except it's a Food artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life," and it loses all other card types.

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Nyx Weaver

Reach
At the beginning of your upkeep, mill two cards. (Put the top two cards of your library into your graveyard.)
{1}{B}{G}, Exile Nyx Weaver: Return target card from your graveyard to your hand.

Swamp

Penumbra Spider

Reach
When Penumbra Spider dies, create a 2/4 black Spider creature token with reach.

Ambuscade

Target creature you control gets +1/+0 until end of turn. It deals damage equal to its power to target creature an opponent controls.

Cosmic Hunger

Target creature you control deals damage equal to its power to another target creature, planeswalker, or battle.

Bite Down

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

Drider

Reach
Whenever Drider deals combat damage to a player, create a 2/1 black Spider creature token with menace and reach.

Prizefight

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Kessig Recluse

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Rotwidow Pack

Reach
{3}{B}{G}, Exile a creature card from your graveyard: Create a 1/2 green Spider creature token with reach, then each opponent loses 1 life for each Spider you control.

Epic Confrontation

Target creature you control gets +1/+2 until end of turn. It fights target creature you don't control. (Each deals damage equal to its power to the other.)

Twin-Silk Spider

Reach
When Twin-Silk Spider enters, create a 1/2 green Spider creature token with reach.

Back for More

Return target creature card from your graveyard to the battlefield. When you do, it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)

Grim Contest

Choose target creature you control and target creature an opponent controls. Each of those creatures deals damage equal to its toughness to the other.

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.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Arena

{3}, {T}: Tap target creature you control and target creature of an opponent's choice they control. Those creatures fight each other. (Each deals damage equal to its power to the other.)

Nature's Way

Target creature you control gains vigilance and trample until end of turn. It deals damage equal to its power to target creature you don't control.

Hunt the Weak

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Aggressive Instinct

Target creature you control deals damage equal to its power to target creature you don't control.

Chainweb Aracnir

Reach
When Chainweb Aracnir enters, it deals damage equal to its power to target creature with flying an opponent controls.
Escape—{3}{G}{G}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Chainweb Aracnir escapes with three +1/+1 counters on it.

Devouring Tendrils

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control. When the permanent you don't control dies this turn, you gain 2 life.

Forest

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Shelob, Dread Weaver

Whenever a nontoken creature an opponent controls dies, exile it.
{2}{B}, Put a creature card exiled with Shelob, Dread Weaver into its owner's graveyard: Put two +1/+1 counters on Shelob. Draw a card.
{X}{1}{B}: Put target creature card with mana value X exiled with Shelob onto the battlefield tapped under your control.

Tower Above

({2/G} can be paid with any two mana or with {G}. This card's mana value is 6.)
Until end of turn, target creature gets +4/+4 and gains trample, wither, and "When this creature attacks, target creature blocks it this turn if able." (It deals damage to creatures in the form of -1/-1 counters.)

Tangle Spider

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Hunter's Edge

Put a +1/+1 counter on target creature you control. Then that creature deals damage equal to its power to target creature you don't control.

Ancient Animus

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Time to Feed

Choose target creature an opponent controls. When that creature dies this turn, you gain 3 life. Target creature you control fights that creature. (Each deals damage equal to its power to the other.)

Watcher in the Web

Reach (This creature can block creatures with flying.)
Watcher in the Web can block an additional seven creatures each combat.

Master's Rebuke

Obelisk Spider

Reach
Whenever Obelisk Spider deals combat damage to a creature, put a -1/-1 counter on that creature.
Whenever you put one or more -1/-1 counters on a creature, each opponent loses 1 life and you gain 1 life.

Lolth, Spider Queen

Whenever a creature you control dies, put a loyalty counter on Lolth, Spider Queen.
0: You draw a card and you lose 1 life.
−3: Create two 2/1 black Spider creature tokens with menace and reach.
−8: You get an emblem with "Whenever an opponent is dealt combat damage by one or more creatures you control, if that player lost less than 8 life this turn, they lose life equal to the difference."

Stew the Coneys

Target creature you control deals damage equal to its power to target creature you don't control. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Spider Spawning

Create a 1/2 green Spider creature token with reach for each creature card in your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Animist's Might

This spell costs {2} less to cast if it targets a legendary creature you control.
Target creature you control deals damage equal to twice its power to target creature or planeswalker you don't control.

Curse of Clinging Webs

Enchant player
Whenever a nontoken creature enchanted player controls dies, exile it and you create a 1/2 green Spider creature token with reach.

Gilded Lotus

Deadly Recluse

Outmuscle

Put a +1/+1 counter on target creature you control, then it fights target creature you don't control. (Each deals damage equal to its power to the other.)
Adamant — If at least three green mana was spent to cast this spell, the creature you control gains indestructible until end of turn.

King Harald's Revenge

Until end of turn, target creature gets +1/+1 for each creature you control and gains trample. It must be blocked this turn if able.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Deadly Allure

Target creature gains deathtouch until end of turn and must be blocked this turn if able.
Flashback {G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sweet-Gum Recluse

Flash
Cascade
Reach
When Sweet-Gum Recluse enters, put three +1/+1 counters on each of any number of target creatures that entered this turn.

Brood Weaver

Reach
When Brood Weaver dies, create a 1/2 green Spider creature token with reach.

Ishkanah, Grafwidow

Reach
Delirium — When Ishkanah, Grafwidow enters, if there are four or more card types among cards in your graveyard, create three 1/2 green Spider creature tokens with reach.
{6}{B}: Target opponent loses 1 life for each Spider you control.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Sol Ring

Doom Weaver

Reach
Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Doom Weaver is paired with another creature, each of those creatures has "When this creature dies, draw cards equal to its power."

Arachnogenesis

Create X 1/2 green Spider creature tokens with reach, where X is the number of creatures attacking you. Prevent all combat damage that would be dealt this turn by non-Spider creatures.

Irresistible Prey

Target creature must be blocked this turn if able.
Draw a card.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

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.)

Clear Shot

Target creature you control gets +1/+1 until end of turn. It deals damage equal to its power to target creature you don't control.

Silklash Spider

Reach
{X}{G}{G}: Silklash Spider deals X damage to each creature with flying.

Sporeweb Weaver

Reach, hexproof from blue
Whenever Sporeweb Weaver is dealt damage, you gain 1 life and create a 1/1 green Saproling creature token.

Lothlórien Blade

Whenever equipped creature attacks, it deals damage equal to its power to target creature defending player controls.
Equip Elf {2}
Equip {5}

Spitting Spider

Reach (This creature can block creatures with flying.)
Sacrifice a land: Spitting Spider deals 1 damage to each creature with flying.