Dragonlair Spider

Reach
Whenever an opponent casts a spell, create a 1/1 green Insect creature token.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice this land: Put your commander into your hand from the command zone.

Amazing Spider-Man

Vigilance, reach
Each legendary spell you cast that's one or more colors has web-slinging {G}{W}{U}. (You may cast a spell for its web-slinging cost if you also return a tapped creature you control to its owner's hand.)

Peter Parker

When Peter Parker enters, create a 2/1 green Spider creature token with reach.
{1}{G}{W}{U}: Transform Peter Parker. Activate only as a sorcery.

Peter Parker // Amazing Spider-Man

Symbiote Spider-Man

Whenever this creature deals combat damage to a player, look at that many cards from the top of your library. Put one of them into your hand and the rest into your graveyard.
Find New Host — {2}{U/B}, Exile this card from your graveyard: Put a +1/+1 counter on target creature you control. It gains this card's other abilities. Activate only as a sorcery.

Cosmic Spider-Man

Flying, first strike, trample, lifelink, haste
At the beginning of combat on your turn, other Spiders you control gain flying, first strike, trample, lifelink, and haste until end of turn.

Drider

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

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.

Araña, Heart of the Spider

Whenever you attack, put a +1/+1 counter on target attacking creature.
Whenever a modified creature you control deals combat damage to a player, exile the top card of your library. You may play that card this turn. (Equipment, Auras you control, and counters are modifications.)

Lolth, Spider Queen

Whenever a creature you control dies, put a loyalty counter on Lolth.
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."

Island

Giant Spider

Reach (This creature can block creatures with flying.)

Arcane Signet

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

Swarmyard Massacre

Create two 1/1 green Squirrel creature tokens. Then each creature that isn't an Insect, Rat, Spider, or Squirrel gets -1/-1 until end of turn for each creature you control that's an Insect, Rat, Spider, or Squirrel.

Spider-Verse

The "legend rule" doesn't apply to Spiders you control.
Whenever you cast a spell from anywhere other than your hand, you may copy it. If you do, you may choose new targets for the copy. If the copy is a permanent spell, it gains haste. Do this only once each turn.

Spider-Man, Web-Slinger

Web-slinging {W} (You may cast this spell for {W} if you also return a tapped creature you control to its owner's hand.)

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.)

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Ultimate Spider-Man

First strike, haste
Camouflage — {2}: Put a +1/+1 counter on Ultimate Spider-Man. He gains hexproof and becomes colorless until end of turn.
Whenever you attack, double the number of each kind of counter on each Spider and legendary creature you control.

Miles Morales

When Miles Morales enters, put a +1/+1 counter on each of up to two target creatures.
{3}{R}{G}{W}: Transform Miles Morales. Activate only as a sorcery.

Miles Morales // Ultimate Spider-Man

Timeless Lotus

Timeless Lotus enters tapped.
{T}: Add {W}{U}{B}{R}{G}.

Mountain

Silklash Spider

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

Obelisk of Esper

Shelob, Dread Weaver

Whenever a nontoken creature an opponent controls dies, exile it.
{2}{B}, Put a creature card exiled with Shelob 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.

Radioactive Spider

Reach, deathtouch
Fateful Bite — {2}, Sacrifice this creature: Search your library for a Spider Hero card, reveal it, put it into your hand, then shuffle. Activate only as a sorcery.

Thantis, the Warweaver

Vigilance, reach
All creatures attack each combat if able.
Whenever a creature attacks you or a planeswalker you control, put a +1/+1 counter on Thantis.

Mary Jane Watson

Whenever a Spider you control enters, draw a card. This ability triggers only once each turn.

Skyfisher Spider

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

Sweet-Gum Recluse

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

Swamp

Giant Trap Door Spider

{1}{R}{G}, {T}: Exile this creature and target creature without flying that's attacking you.

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 this creature: Return target card from your graveyard to your hand.

Plains

Sol Ring

Spider-Man, Brooklyn Visionary

Web-slinging {2}{G} (You may cast this spell for {2}{G} if you also return a tapped creature you control to its owner's hand.)
When Spider-Man enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Spectacular Spider-Man

Flash
{1}: Spectacular Spider-Man gains flying until end of turn.
{1}, Sacrifice Spectacular Spider-Man: Creatures you control gain hexproof and indestructible until end of turn.

Chainweb Aracnir

Reach
When this creature 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.)
This creature escapes with three +1/+1 counters on it.

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."

Silk, Web Weaver

Web-slinging {1}{G}{W} (You may cast this spell for {1}{G}{W} if you also return a tapped creature you control to its owner's hand.)
Whenever you cast a creature spell, create a 1/1 green and white Human Citizen creature token.
{3}{G}{W}: Creatures you control get +2/+2 and gain vigilance until end of turn.

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.

Spider-Man, Miles Morales

Vigilance, trample (Attacking doesn't cause this creature to tap. He can deal excess combat damage to the player he's attacking.)
Whenever Spider-Man enters or attacks, put a +1/+1 counter on each other creature you control. Those creatures gain trample until end of turn.

Spider-Man 2099

From the Future — You can't cast Spider-Man 2099 during your first, second, or third turns of the game.
Double strike, vigilance
At the beginning of your end step, if you've played a land or cast a spell this turn from anywhere other than your hand, Spider-Man 2099 deals damage equal to his power to any target.

Ghost-Spider, Gwen Stacy

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Ghost-Spider attacks, she deals X damage to defending player, where X is the number of attacking creatures.

Spider-Punk

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Other Spiders you control have riot.
Spells and abilities can't be countered.
Damage can't be prevented.

Obelisk of Grixis

Aunt May

Whenever another creature you control enters, you gain 1 life. If it's a Spider, put a +1/+1 counter on it.

Spider Manifestation

Reach
{T}: Add {R} or {G}.
Whenever you cast a spell with mana value 4 or greater, untap this creature.

The Swarmweaver

When The Swarmweaver enters, create two 1/1 black and green Insect creature tokens with flying.
Delirium — As long as there are four or more card types among cards in your graveyard, Insects and Spiders you control get +1/+1 and have deathtouch.

Forest

Web of Life and Destiny

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
At the beginning of combat on your turn, look at the top five cards of your library. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Ishkanah, Grafwidow

Reach
Delirium — When Ishkanah 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.

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 token: You gain 3 life," and it loses all other card types.

Obelisk of Bant

Command Tower

Sporeweb Weaver

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

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Spider-Ham, Peter Porker

When Spider-Ham enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Animal May-Ham — Other Spiders, Boars, Bats, Bears, Birds, Cats, Dogs, Frogs, Jackals, Lizards, Mice, Otters, Rabbits, Raccoons, Rats, Squirrels, Turtles, and Wolves you control get +1/+1.

Spinner of Souls

Reach
Whenever another nontoken creature you control dies, you may reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.

Obelisk of Naya

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.)