Snow-Covered Plains

Dreamtail Heron

Mutate {3}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying
Whenever this creature mutates, draw a card.

Fellwar Stone

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

Fountain of Ichor

{T}: Add one mana of any color.
{3}: This artifact becomes a 3/3 Dinosaur artifact creature until end of turn.

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Izzet Guildgate

This land enters tapped.
{T}: Add {U} or {R}.

Sea Gate

This land enters tapped.
As this land enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Snow-Covered Swamp

Orzhov Guildgate

This land enters tapped.
{T}: Add {W} or {B}.

Reaping the Graves

Return target creature card from your graveyard to your hand.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Dig Up the Body

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell.)
Mill two cards, then you may return a creature card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Migratory Greathorn

Mutate {2}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Snow-Covered Forest

Selesnya Guildgate

This land enters tapped.
{T}: Add {G} or {W}.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Disturbing Plot

Return target creature card from a graveyard to its owner's hand.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Rakdos Guildgate

This land enters tapped.
{T}: Add {B} or {R}.

Vulpikeet

Mutate {2}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying
Whenever this creature mutates, put a +1/+1 counter on it.

Snow-Covered Mountain

Black Dragon Gate

This land enters tapped.
As this land enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Golgari Guildgate

This land enters tapped.
{T}: Add {B} or {G}.

Cavern Whisperer

Mutate {3}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Menace (This creature can't be blocked except by two or more creatures.)
Whenever this creature mutates, each opponent discards a card.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Basilisk Gate

{T}: Add {C}.
{2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

Gateway Plaza

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Manor Gate

This land enters tapped.
As this land enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Citadel Gate

This land enters tapped.
As this land enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Teach by Example

({U/R} can be paid with either {U} or {R}.)
When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Snow-Covered Island

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Mysterious Egg

Whenever this creature mutates, put a +1/+1 counter on it.

Essence Symbiote

Whenever a creature you control mutates, put a +1/+1 counter on that creature and you gain 2 life.

Cloudpiercer

Mutate {3}{R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Reach
Whenever this creature mutates, you may discard a card. If you do, draw a card.

Gruul Guildgate

This land enters tapped.
{T}: Add {R} or {G}.

Cliffgate

This land enters tapped.
As this land enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.