Wingrattle Scarecrow

Wingrattle Scarecrow has flying as long as you control a blue creature.
Wingrattle Scarecrow has persist as long as you control a black creature. (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.)

Aether Tunnel

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked.

Leyline of the Guildpact

If Leyline of the Guildpact is in your opening hand, you may begin the game with it on the battlefield.
Each nonland permanent you control is all colors.
Lands you control are every basic land type in addition to their other types.

Pili-Pala

Flying
{2}, {Q}: Add one mana of any color. ({Q} is the untap symbol.)

Greed

Chromatic Lantern

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

Command Tower

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

Jousting Dummy

{3}: Jousting Dummy gets +1/+0 until end of turn.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

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.)

Fang Skulkin

{2}: Target black creature gains wither until end of turn. (It deals damage to creatures in the form of -1/-1 counters.)

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Death Grasp

Death Grasp deals X damage to any target. You gain X life.

Panharmonicon

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

Arcane Signet

Door to Nothingness

Door to Nothingness enters the battlefield tapped.
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice Door to Nothingness: Target player loses the game.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Painter's Servant

As Painter's Servant enters the battlefield, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Archaeomancer

When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Arcane Lighthouse

{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

Blazethorn Scarecrow

Blazethorn Scarecrow has haste as long as you control a red creature.
Blazethorn Scarecrow has wither as long as you control a green creature. (It deals damage to creatures in the form of -1/-1 counters.)

Mind Bend

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Sword of Light and Shadow

Equipped creature gets +2/+2 and has protection from white and from black.
Whenever equipped creature deals combat damage to a player, you gain 3 life and you may return up to one target creature card from your graveyard to your hand.
Equip {2}

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.

Scrapbasket

{1}: Scrapbasket becomes all colors until end of turn.

Cover of Darkness

As Cover of Darkness enters the battlefield, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Mycosynth Lattice

All permanents are artifacts in addition to their other types.
All cards that aren't on the battlefield, spells, and permanents are colorless.
Players may spend mana as though it were mana of any color.

Shell Skulkin

{3}: Target blue creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Rattleblaze Scarecrow

Rattleblaze Scarecrow has persist as long as you control a black creature. (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.)
Rattleblaze Scarecrow has haste as long as you control a red creature.

Blind Seer

{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.

Jawbone Skulkin

{2}: Target red creature gains haste until end of turn.

Etherium Sculptor

Artifact spells you cast cost {1} less to cast.

Grand Architect

Other blue creatures you control get +1/+1.
{U}: Target artifact creature becomes blue until end of turn.
Tap an untapped blue creature you control: Add {C}{C}. Spend this mana only to cast artifact spells or activate abilities of artifacts.

The World Tree

The World Tree enters the battlefield tapped.
{T}: Add {G}.
As long as you control six or more lands, lands you control have "{T}: Add one mana of any color."
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice The World Tree: Search your library for any number of God cards, put them onto the battlefield, then shuffle.

And They Shall Know No Fear

Choose a creature type. Creatures you control of the chosen type get +1/+0 and gain indestructible until end of turn.

Naked Singularity

Cumulative upkeep {3} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
If tapped for mana, Plains produce {R}, Islands produce {G}, Swamps produce {W}, Mountains produce {U}, and Forests produce {B} instead of any other type.

Roar of the Crowd

Choose a creature type. Roar of the Crowd deals damage to any target equal to the number of permanents you control of the chosen type.

Archaeomender

When Archaeomender enters the battlefield, return target artifact card from your graveyard to your hand.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Thornwatch Scarecrow

Thornwatch Scarecrow has wither as long as you control a green creature. (It deals damage to creatures in the form of -1/-1 counters.)
Thornwatch Scarecrow has vigilance as long as you control a white creature.

Nylea, God of the Hunt

Indestructible
As long as your devotion to green is less than five, Nylea isn't a creature. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Other creatures you control have trample.
{3}{G}: Target creature gets +2/+2 until end of turn.

Watchwing Scarecrow

Watchwing Scarecrow has vigilance as long as you control a white creature.
Watchwing Scarecrow has flying as long as you control a blue creature.

Cultivate

Farseek

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

Changeling Outcast

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

Scarecrone

{1}, Sacrifice a Scarecrow: Draw a card.
{4}, {T}: Return target artifact creature card from your graveyard to the battlefield.

Gandalf the White

Flash
You may cast legendary spells and artifact spells as though they had flash.
If a legendary permanent or an artifact entering or leaving the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Sword of Hearth and Home

Equipped creature gets +2/+2 and has protection from green and from white.
Whenever equipped creature deals combat damage to a player, exile up to one target creature you own, then search your library for a basic land card. Put both cards onto the battlefield under your control, then shuffle.
Equip {2}

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, Temur Sabertooth gains indestructible until end of turn.

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Reaper King

({2/W} can be paid with any two mana or with {W}. This card's mana value is 10.)
Other Scarecrow creatures you control get +1/+1.
Whenever another Scarecrow enters the battlefield under your control, destroy target permanent.

Black Scarab

Enchant creature
Enchanted creature can't be blocked by black creatures.
Enchanted creature gets +2/+2 as long as an opponent controls a black permanent.

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Hoof Skulkin

{3}: Target green creature gets +1/+1 until end of turn.

Sol Ring

Mirror March

Whenever a nontoken creature enters the battlefield under your control, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Borne Upon a Wind

You may cast spells this turn as though they had flash.
Draw a card.

Deathgrip

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)