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.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Treetop Snarespinner

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
{2}{G}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

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.

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.

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.

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.

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.)

Broodspinner

Reach
When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
{4}{B}{G}, {T}, Sacrifice this creature: Create a number of 1/1 black and green Insect creature tokens with flying equal to the number of card types among cards in your graveyard.

Twin-Silk Spider

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

Brood Weaver

Reach
When this creature dies, create a 1/2 green Spider creature token with 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.

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.

Hatchery Spider

Reach
Undergrowth — When you cast this spell, reveal the top X cards of your library, where X is the number of creature cards in your graveyard. You may put a green permanent card with mana value X or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

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.

Arcane Signet

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

Mirkwood Spider

Deathtouch
Whenever this creature attacks, target legendary creature you control gains deathtouch until end of turn.

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."

Obelisk Spider

Reach
Whenever this creature 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.

Cultivate

Penumbra Spider

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

Watcher in the Web

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

Silklash Spider

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

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.)

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.

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.

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.

Sol Ring

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Summoning Materia

You may look at the top card of your library any time.
As long as this Equipment is attached to a creature, you may cast creature spells from the top of your library.
Equipped creature gets +2/+2 and has vigilance and "{T}: Add {G}."
Equip {2}

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Drider

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

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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 card from your graveyard.

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.

Izoni, Center of the Web

Menace
Whenever Izoni enters or attacks, you may collect evidence 4. If you do, create two 2/1 black and green Spider creature tokens with menace and reach.
Sacrifice four tokens: Surveil 2, then draw two cards. You gain 2 life.

Ruins Recluse

Reach, deathtouch
{3}{G}: Put a +1/+1 counter on this creature.

Commune with Nature

Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Llanowar Greenwidow

Reach, trample
Domain — {7}{G}: Return this card 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.

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."