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.

Boggart Mob

Champion a Goblin (When this enters, sacrifice it unless you exile another Goblin you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever a Goblin you control deals combat damage to a player, you may create a 1/1 black Goblin Rogue creature token.

Scalding Tarn

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

Fire-Belly Changeling

Changeling (This card is every creature type.)
{R}: Fire-Belly Changeling gets +1/+0 until end of turn. Activate no more than twice each turn.

Windswept Heath

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

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Ghostly Changeling

Changeling (This card is every creature type.)
{1}{B}: Ghostly Changeling gets +1/+1 until end of turn.

Simic Signet

Exotic Orchard

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

Rakdos Signet

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.

Island

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Azorius Signet

Woodland Changeling

Changeling (This card is every creature type.)

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Utopia Sprawl

Enchant Forest
As Utopia Sprawl enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

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.

Gruul Signet

Soul Warden

Whenever another creature enters, you gain 1 life.

Chromatic Lantern

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

Misty Rainforest

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

Supreme Exemplar

Flying
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Shapesharer

Changeling (This card is every creature type.)
{2}{U}: Target Shapeshifter becomes a copy of target creature until your next turn.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Golos, Tireless Pilgrim

When Golos, Tireless Pilgrim enters, you may search your library for a land card, put that card onto the battlefield tapped, then shuffle.
{2}{W}{U}{B}{R}{G}: Exile the top three cards of your library. You may play them this turn without paying their mana costs.

Izzet Signet

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.

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.

Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Snow-Covered Forest

Essence Warden

Impostor of the Sixth Pride

Moonglove Changeling

Changeling (This card is every creature type.)
{B}: Moonglove Changeling gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy that creature.)

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Changeling Berserker

Changeling (This card is every creature type.)
Haste
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)

Golgari Signet

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters, you may return target creature card from your graveyard to your hand.

Wren's Run Packmaster

Champion an Elf (When this creature enters, sacrifice it unless you exile another Elf you control. When this creature leaves the battlefield, that card returns to the battlefield.)
{2}{G}: Create a 2/2 green Wolf creature token.
Wolves you control have deathtouch.

Thoughtweft Trio

First strike, vigilance
Champion a Kithkin (When this enters, sacrifice it unless you exile another Kithkin you control. When this leaves the battlefield, that card returns to the battlefield.)
Thoughtweft Trio can block any number of creatures.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Ramunap Excavator

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.

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.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Changeling Outcast

Changeling (This card is every creature type.)
Changeling Outcast can't block and can't be blocked.

Selesnya Signet

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Molten Echoes

As Molten Echoes enters, choose a creature type.
Whenever a nontoken creature you control of the chosen type enters, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Boros Signet

Orzhov Signet

Venomous Changeling

Changeling (This card is every creature type.)
Deathtouch

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.

Flooded Strand

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

Skeletal Changeling

Changeling (This card is every creature type.)
{1}{B}: Regenerate Skeletal Changeling.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Wanderwine Prophets

Champion a Merfolk (When this enters, sacrifice it unless you exile another Merfolk you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever Wanderwine Prophets deals combat damage to a player, you may sacrifice a Merfolk. If you do, take an extra turn after this one.

Nova Chaser

Trample
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Changeling Titan

Changeling (This card is every creature type.)
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Unstoppable Ash

Trample
Champion a Treefolk or Warrior (When this enters, sacrifice it unless you exile another Treefolk or Warrior you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever a creature you control becomes blocked, it gets +0/+5 until end of turn.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Universal Automaton

Snow-Covered Swamp

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: Mothdust Changeling gains flying until end of turn.

Mountain

Changeling Hero

Changeling (This card is every creature type.)
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

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.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Arcane Signet

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

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on this creature.

Command Tower

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Snow-Covered Plains

Mina and Denn, Wildborn

You may play an additional land on each of your turns.
{R}{G}, Return a land you control to its owner's hand: Target creature gains trample until end of turn.

Phylath, World Sculptor

When Phylath, World Sculptor enters, create a 0/1 green Plant creature token for each basic land you control.
Landfall — Whenever a land you control enters, put four +1/+1 counters on target Plant you control.

Dual Nature

Whenever a nontoken creature enters, its controller creates a token that's a copy of that creature.
Whenever a nontoken creature leaves the battlefield, exile all tokens with the same name as that creature.
When Dual Nature leaves the battlefield, exile all tokens created with Dual Nature.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.