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.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Snow-Covered Swamp

Farseek

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

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Command Tower

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

Corpse Connoisseur

When Corpse Connoisseur enters, you may search your library for a creature card, put that card into your graveyard, then shuffle.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Snow-Covered Mountain

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Verdurous Gearhulk

Trample
When Verdurous Gearhulk enters, distribute four +1/+1 counters among any number of target creatures you control.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Woodfall Primus

Trample
When Woodfall Primus enters, destroy target noncreature permanent.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Sepulchral Primordial

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When Sepulchral Primordial enters, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.

Thragtusk

When Thragtusk enters, you gain 5 life.
When Thragtusk leaves the battlefield, create a 3/3 green Beast creature token.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Yavimaya Elder

When Yavimaya Elder dies, you may search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
{2}, Sacrifice Yavimaya Elder: Draw a card.

Mana Confluence

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

Grisly Salvage

Reveal the top five cards of your library. You may put a creature or land card from among them into your hand. Put the rest into your graveyard.

Parallel Lives

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

Birds of Paradise

Beast Within

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

Sundial of the Infinite

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

Underrealm Lich

If you would draw a card, instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard.
Pay 4 life: Underrealm Lich gains indestructible until end of turn. Tap it.

Fires of Yavimaya

Creatures you control have haste.
Sacrifice Fires of Yavimaya: Target creature gets +2/+2 until end of turn.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Entomb

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

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Greater Good

Sacrifice a creature: Draw cards equal to the sacrificed creature's power, then discard three cards.

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

World Shaper

Whenever World Shaper attacks, you may mill three cards.
When World Shaper dies, return all land cards from your graveyard to the battlefield tapped.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Harmonize

Evolutionary Leap

{G}, Sacrifice a creature: 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.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Combustible Gearhulk

First strike
When Combustible Gearhulk enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then Combustible Gearhulk deals damage to that player equal to the total mana value of those cards.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Nature's Lore

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

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Stomping Ground

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

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Gyrus, Waker of Corpses

Gyrus, Waker of Corpses enters with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.
Whenever Gyrus attacks, you may exile target creature card with lesser power from your graveyard. If you do, create a token that's a copy of that card and that's tapped and attacking. Exile the token at end of combat.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Disciple of Bolas

When Disciple of Bolas enters, sacrifice another creature. You gain X life and draw X cards, where X is that creature's power.

Hunter's Insight

Choose target creature you control. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

Golgari Thug

When Golgari Thug dies, put target creature card from your graveyard on top of your library.
Dredge 4 (If you would draw a card, you may mill four cards instead. If you do, return this card from your graveyard to your hand.)

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Ancient Grudge

Destroy target artifact.
Flashback {G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Phyrexian Delver

When Phyrexian Delver enters, return target creature card from your graveyard to the battlefield. You lose life equal to that card's mana value.

Blood Crypt

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

Overgrown Tomb

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

Ramunap Excavator

Cavalier of Thorns

Reach
When Cavalier of Thorns enters, reveal the top five cards of your library. Put a land card from among them onto the battlefield and the rest into your graveyard.
When Cavalier of Thorns dies, you may exile it. If you do, put another target card from your graveyard on top of your library.

Marsh Flats

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

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Arid Mesa

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

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Sol Ring

Grapple with the Past

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Mulch

Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

Lithoform Engine

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Satyr Wayfinder

When Satyr Wayfinder enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Snow-Covered Forest

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.