From Under the Floorboards

Madness {X}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
Create three tapped 2/2 black Zombie creature tokens and you gain 3 life. If this spell's madness cost was paid, instead create X of those tokens and you gain X life.

Canopy Stalker

Canopy Stalker must be blocked if able.
When Canopy Stalker dies, you gain 1 life for each creature that died this turn.

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."

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Gibbering Barricade

Defender
{2}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Letter of Acceptance

{T}: Add one mana of any color.
{2}, {T}, Sacrifice Letter of Acceptance: Draw a card.

Command Tower

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

Without Weakness

Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it. If its toughness is 0 or less, it's still put into its owner's graveyard.)
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Funnel-Web Recluse

Reach
Morbid — When Funnel-Web Recluse enters the battlefield, if a creature died this turn, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Deathcap Cultivator

{T}: Add {B} or {G}.
Delirium — Deathcap Cultivator has deathtouch as long as there are four or more card types among cards in your graveyard.

Overgrowth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}{G}.

Moss Diamond

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

Gaea's Gift

Put a +1/+1 counter on target creature you control. It gains reach, trample, hexproof, and indestructible until end of turn. (It can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Giant Spider

Reach (This creature can block creatures with flying.)

Flourishing Strike

Choose one —
• Flourishing Strike deals 5 damage to target creature with flying.
• Target creature gets +3/+3 until end of turn.
Entwine {2}{G} (Choose both if you pay the entwine cost.)

Canopy Spider

Acid Web Spider

Reach
When Acid Web Spider enters the battlefield, you may destroy target Equipment.

Sporecap Spider

Juvenile Gloomwidow

Reach (This creature can block creatures with flying.)
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Somberwald Spider

Reach (This creature can block creatures with flying.)
Morbid — Somberwald Spider enters the battlefield with two +1/+1 counters on it if a creature died this turn.

Jungle Hollow

Jungle Hollow enters the battlefield tapped.
When Jungle Hollow enters the battlefield, you gain 1 life.
{T}: Add {B} or {G}.

Golgari Rot Farm

Golgari Rot Farm enters the battlefield tapped.
When Golgari Rot Farm enters the battlefield, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Snarespinner

Reach
Whenever Snarespinner blocks a creature with flying, Snarespinner gets +2/+0 until end of turn.

Honored Heirloom

{T}: Add one mana of any color.
{2}, {T}: Exile target card from a graveyard.

Copper Longlegs

Reach
{1}{G}, Sacrifice Copper Longlegs: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Murder

Gravedigger

When Gravedigger enters the battlefield, you may return target creature card from your graveyard to your hand.

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.

Kazandu Nectarpot

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

Skyfisher Spider

Reach
When Skyfisher Spider enters the battlefield, you may sacrifice another creature. When you do, destroy target nonland permanent.
When Skyfisher Spider dies, you may gain 1 life for each creature card in your graveyard. If you do, exile Skyfisher Spider from your graveyard.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Incremental Growth

Put a +1/+1 counter on target creature, two +1/+1 counters on another target creature, and three +1/+1 counters on a third target creature.

Mind Stone

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

Drider

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

Wall of Vines

Defender (This creature can't attack.)
Reach (This creature can block creatures with flying.)

Llanowar Greenwidow

Reach, trample
Domain — {7}{G}: Return Llanowar Greenwidow from your graveyard to the battlefield tapped. It gains "If this permanent would leave the battlefield, exile it instead of putting it anywhere else." This ability costs {1} less to activate for each basic land type among lands you control.

Roar of Challenge

All creatures able to block target creature this turn do so.
Ferocious — That creature gains indestructible until end of turn if you control a creature with power 4 or greater.

Naturalize

Stingerfling Spider

Reach
When Stingerfling Spider enters the battlefield, you may destroy target creature with flying.

Ishkanah, Grafwidow

Reach
Delirium — When Ishkanah, Grafwidow enters the battlefield, 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.

Arcane Signet

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Hydra's Growth

Enchant creature
When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

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.

Netcaster Spider

Reach (This creature can block creatures with flying.)
Whenever Netcaster Spider blocks a creature with flying, Netcaster Spider gets +2/+0 until end of turn.

Returned Reveler

When Returned Reveler dies, each player mills three cards.

Arachnus Spinner

Reach
Tap an untapped Spider you control: Search your graveyard and/or library for a card named Arachnus Web and put it onto the battlefield attached to target creature. If you search your library this way, shuffle.

Vraska, Swarm's Eminence

Whenever a creature you control with deathtouch deals damage to a player or planeswalker, put a +1/+1 counter on that creature.
−2: Create a 1/1 black Assassin creature token with deathtouch and "Whenever this creature deals damage to a planeswalker, destroy that planeswalker."

Watcher in the Web

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

Sentinel Spider

Frostweb Spider

Reach (This creature can block creatures with flying.)
Whenever Frostweb Spider blocks a creature with flying, put a +1/+1 counter on Frostweb Spider at end of combat.

Blightwidow

Reach (This creature can block creatures with flying.)
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Temple of Malady

Temple of Malady enters the battlefield tapped.
When Temple of Malady enters the battlefield, scry 1.
{T}: Add {B} or {G}.

Mammoth Spider

Oakenform

Enchant creature
Enchanted creature gets +3/+3.

Hitchclaw Recluse

Rot Shambler

Whenever another creature you control dies, put a +1/+1 counter on Rot Shambler.

Ulvenwald Hydra

Reach
Ulvenwald Hydra's power and toughness are each equal to the number of lands you control.
When Ulvenwald Hydra enters the battlefield, you may search your library for a land card, put it onto the battlefield tapped, then shuffle.

Urborg Repossession

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
Return target creature card from your graveyard to your hand. You gain 2 life. If this spell was kicked, return another target permanent card from your graveyard to your hand.

Molderhulk

Undergrowth — This spell costs {1} less to cast for each creature card in your graveyard.
When Molderhulk enters the battlefield, return target land card from your graveyard to the battlefield.

Sol Ring

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.)

Arachnoform

Enchant creature
Enchanted creature gets +2/+2, has reach, and is every creature type.

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.")

Barrier of Bones

Defender
When Barrier of Bones enters the battlefield, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Maze Abomination

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Multicolored creatures you control have deathtouch.

Penumbra Spider

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

Swamp

Gloomwidow

Reach
Gloomwidow can block only creatures with flying.

Farbog Revenant

Skulk (This creature can't be blocked by creatures with greater power.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Silklash Spider

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

Forest

Deadly Recluse

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

Cultivate

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.

Oran-Rief Recluse

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Reach (This creature can block creatures with flying.)
When Oran-Rief Recluse enters the battlefield, if it was kicked, destroy target creature with flying.

Contest of Claws

Target creature you control deals damage equal to its power to another target creature. If excess damage was dealt this way, discover X, where X is that excess damage. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Doom Weaver

Reach
Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. 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."

Chainweb Aracnir

Reach
When Chainweb Aracnir enters the battlefield, 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.

Cemetery Recruitment

Return target creature card from your graveyard to your hand. If it's a Zombie card, draw a card.

Titanic Growth

Target creature gets +4/+4 until end of turn.

Graverobber Spider

Reach
{3}{B}: Graverobber Spider gets +X/+X until end of turn, where X is the number of creature cards in your graveyard. Activate only once each turn.

Twin-Silk Spider

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