Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Curse of Opulence

Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this artifact: Add one mana of any color.")

Mountain

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Endless Whispers

Each creature has "When this creature dies, choose target opponent. That player puts this card from its owner's graveyard onto the battlefield under their control at the beginning of the next end step."

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.

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, the Warweaver.

Sokenzan, Crucible of Defiance

{T}: Add {R}.
Channel — {3}{R}, Discard Sokenzan, Crucible of Defiance: Create two 1/1 colorless Spirit creature tokens. They gain haste until end of turn. This ability costs {1} less to activate for each legendary creature you control.

Trove of Temptation

Each opponent must attack you or a planeswalker you control with at least one creature each combat if able.
At the beginning of your end step, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Deathreap Ritual

Morbid — At the beginning of each end step, if a creature died this turn, you may draw a card.

Mirkwood Spider

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

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.

Curse of Bounty

Enchant player
Whenever enchanted player is attacked, untap all nonland permanents you control. Each opponent attacking that player untaps all nonland permanents they control.

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

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."

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Command Tower

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

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

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.

Juvenile Gloomwidow

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

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Ziatora's Proving Ground

({T}: Add {B}, {R}, or {G}.)
Ziatora's Proving Ground enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Webspinner Cuff

Reach
Equipped creature gets +1/+4 and has reach.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Tangle

Prevent all combat damage that would be dealt this turn.
Each attacking creature doesn't untap during its controller's next untap step.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Golgari Charm

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

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

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.

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.)

Kardur, Doomscourge

When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Hoarding Recluse

Reach, deathtouch
When Hoarding Recluse dies, put up to one other target card from a graveyard on the bottom of its owner's library.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Heroic Intervention

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

Spitting Spider

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

Hunted Dragon

Flying, haste
When Hunted Dragon enters, target opponent creates three 2/2 white Knight creature tokens with first strike.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Gilded Lotus

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Brood Weaver

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

Shelob's Ambush

Target creature gets +1/+2 and gains deathtouch until end of turn. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Arachnus Web

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.
At the beginning of the end step, if enchanted creature's power is 4 or greater, destroy Arachnus Web.

Phage the Untouchable

When Phage the Untouchable enters, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Kodama of the East Tree

Reach
Whenever another permanent you control enters, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Sower of Discord

Flying
As Sower of Discord enters, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Field of the Dead

Field of the Dead enters tapped.
{T}: Add {C}.
Whenever Field of the Dead or another land you control enters, if you control seven or more lands with different names, create a 2/2 black Zombie creature token.

Deadly Recluse

Constant Mists

Buyback—Sacrifice a land. (You may sacrifice a land in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Prevent all combat damage that would be dealt this turn.

Giant Trap Door Spider

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

Golgari Rot Farm

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

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Stingerfling Spider

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

Vesuva

You may have Vesuva enter tapped as a copy of any land on the battlefield.

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.)

Swarmyard

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

Winds of Qal Sisma

Prevent all combat damage that would be dealt this turn.
Ferocious — If you control a creature with power 4 or greater, instead prevent all combat damage that would be dealt this turn by creatures your opponents control.

Swamp

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.

Spore Cloud

Tap all blocking creatures. Prevent all combat damage that would be dealt this turn. Each attacking creature and each blocking creature doesn't untap during its controller's next untap step.

Lotus Field

Hexproof
Lotus Field enters tapped.
When Lotus Field enters, sacrifice two lands.
{T}: Add three mana of any one color.

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.

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.

Wrap in Vigor

Moment's Peace

Prevent all combat damage that would be dealt this turn.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Blast Zone

Blast Zone enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on Blast Zone.
{3}, {T}, Sacrifice Blast Zone: Destroy each nonland permanent with mana value equal to the number of charge counters on Blast Zone.

Quest for Renewal

Whenever a creature you control becomes tapped, you may put a quest counter on Quest for Renewal.
As long as there are four or more quest counters on Quest for Renewal, untap all creatures you control during each other player's untap step.

Watcher in the Web

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

No Mercy

Whenever a creature deals damage to you, destroy it.

Penumbra Spider

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

Sol Ring

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Arcane Signet

Curse of Disturbance

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Marchesa's Decree

When Marchesa's Decree enters, you become the monarch.
Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

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.)

Twin-Silk Spider

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

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Hunted Horror

Trample
When Hunted Horror enters, target opponent creates two 3/3 green Centaur creature tokens with protection from black.

Respite

Prevent all combat damage that would be dealt this turn. You gain 1 life for each attacking creature.

Ruins Recluse

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

Seedborn Muse

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

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.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Hunted Troll

When Hunted Troll enters, target opponent creates four 1/1 blue Faerie creature tokens with flying.
{G}: Regenerate Hunted Troll.

Forest

Grismold, the Dreadsower

Trample
At the beginning of your end step, each player creates a 1/1 green Plant creature token.
Whenever a creature token dies, put a +1/+1 counter on Grismold, the Dreadsower.

Cultivate

Inkmoth Nexus

{T}: Add {C}.
{1}: Inkmoth Nexus becomes a 1/1 Phyrexian Blinkmoth artifact creature with flying and infect until end of turn. It's still a land. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)