Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Syphon Sliver

Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)

Lavabelly Sliver

Sliver creatures you control have "When this creature enters, it deals 1 damage to target player or planeswalker and you gain 1 life."

Plains

Path of Ancestry

Path of Ancestry enters 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.)

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Brood Sliver

Whenever a Sliver deals combat damage to a player, its controller may create a 1/1 colorless Sliver creature token.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Lazotep Sliver

Sliver creatures you control have afflict 2. (Whenever a creature with afflict 2 becomes blocked, defending player loses 2 life.)
Whenever a nontoken Sliver you control dies, amass Slivers 2. (Put two +1/+1 counters on an Army you control. It's also a Sliver. If you don't control an Army, create a 0/0 black Sliver Army creature token first.)

Swamp

Pillar of Origins

As Pillar of Origins enters, choose a creature type.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Command Tower

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

Winged Sliver

Essence Backlash

Counter target creature spell. Essence Backlash deals damage equal to that spell's power to its controller.

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Diffusion Sliver

Whenever a Sliver creature you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.

Sliver Queen

{2}: Create a 1/1 colorless Sliver creature token.

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

Door of Destinies

As Door of Destinies enters, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Crystalline Sliver

All Slivers have shroud. (They can't be the targets of spells or abilities.)

Exotic Orchard

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

Essence Sliver

Whenever a Sliver deals damage, its controller gains that much life.

Mountain

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Replicated Ring

The First Sliver

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Sliver spells you cast have cascade.

March of the Drowned

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target Pirate cards from your graveyard to your hand.

Sol Ring

Forest

Sliver Hive

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Sliver spell.
{5}, {T}: Create a 1/1 colorless Sliver creature token. Activate only if you control a Sliver.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Bonescythe Sliver

Sliver creatures you control have double strike. (They deal both first-strike and regular combat damage.)

Standardize

Choose a creature type other than Wall. Each creature becomes that type until end of turn.

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Counterspell

Sliver

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Shields of Velis Vel

Changeling (This card is every creature type.)
Creatures target player controls get +0/+1 and gain all creature types until end of turn.

Sliver Gravemother

The "legend rule" doesn't apply to Slivers you control.
Each Sliver creature card in your graveyard has encore {X}, where X is its mana value.
Encore {5} ({5}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Moonsilver Key

{1}, {T}, Sacrifice Moonsilver Key: Search your library for an artifact card with a mana ability or a basic land card, reveal it, put it into your hand, then shuffle.

Magma Sliver

All Slivers have "{T}: Target Sliver creature gets +X/+0 until end of turn, where X is the number of Slivers on the battlefield."

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Rampant Growth

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

Sliver Hivelord

Sliver creatures you control have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Manaweft Sliver

Sliver creatures you control have "{T}: Add one mana of any color."

Seek the Horizon

Search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Unclaimed Territory

As Unclaimed Territory 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.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Firewake Sliver

All Sliver creatures have haste.
All Slivers have "{1}, Sacrifice this permanent: Target Sliver creature gets +2/+2 until end of turn."

Court of Ardenvale

When Court of Ardenvale enters, you become the monarch.
At the beginning of your upkeep, return target permanent card with mana value 3 or less from your graveyard to your hand. If you're the monarch, return that permanent card to the battlefield instead.

Necrotic Sliver

All Slivers have "{3}, Sacrifice this permanent: Destroy target permanent."

Acidic Sliver

All Slivers have "{2}, Sacrifice this permanent: This permanent deals 2 damage to any target."

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Secluded Courtyard

As Secluded Courtyard 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 or activate an ability of a creature source of the chosen type.

Venom Sliver

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

Sliver Legion

All Sliver creatures get +1/+1 for each other Sliver on the battlefield.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Sentinel Sliver

Sliver creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Unnatural Selection

{1}: Choose a creature type other than Wall. Target creature becomes that type until end of turn.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Ancient Ziggurat

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Sliver Army

Sinew Sliver

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)

Amoeboid Changeling

Changeling (This card is every creature type.)
{T}: Target creature gains all creature types until end of turn.
{T}: Target creature loses all creature types until end of turn.

Island

Arcane Signet

The Monarch

At the beginning of your end step, draw a card.
Whenever a creature deals combat damage to you, its controller becomes the monarch.

Sliver Overlord

{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle.
{3}: Gain control of target Sliver. (This effect lasts indefinitely.)

Galerider Sliver

Sliver creatures you control have flying.

Shifting Sliver

Slivers can't be blocked except by Slivers.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Ashnod's Altar

Clot Sliver

All Slivers have "{2}: Regenerate this permanent."

Banner of Kinship

As this artifact enters, choose a creature type. This artifact enters with a fellowship counter on it for each creature you control of the chosen type.
Creatures you control of the chosen type get +1/+1 for each fellowship counter on this artifact.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Vastwood Surge

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If this spell was kicked, put two +1/+1 counters on each creature you control.

Wild Research

{1}{W}: Search your library for an enchantment card and reveal that card. Put it into your hand, then discard a card at random. Then shuffle.
{1}{U}: Search your library for an instant card and reveal that card. Put it into your hand, then discard a card at random. Then shuffle.

Harmonic Sliver

All Slivers have "When this permanent enters, destroy target artifact or enchantment."

Heart Sliver

Getting

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)