Agate Instigator

Offspring {1}{R} (You may pay an additional {1}{R} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever another creature you control enters, this creature deals 1 damage to each opponent.

Devilish Valet

Trample, haste
Alliance — Whenever another creature you control enters, double Devilish Valet's power until end of turn.

Pollywog Prodigy

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever an opponent casts a noncreature spell with mana value less than Pollywog Prodigy's power, draw a card.

Valley Questcaller

Whenever one or more other Rabbits, Bats, Birds, and/or Mice you control enter, scry 1.
Other Rabbits, Bats, Birds, and Mice you control get +1/+1.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Rapid Augmenter

Haste
Whenever another creature you control with base power 1 enters, it gains haste until end of turn.
Whenever another creature you control enters, if it wasn't cast, put a +1/+1 counter on Rapid Augmenter and Rapid Augmenter can't be blocked this turn.

Elspeth, Sun's Champion

+1: Create three 1/1 white Soldier creature tokens.
−3: Destroy all creatures with power 4 or greater.
−7: You get an emblem with "Creatures you control get +2/+2 and have flying."

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

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.")

Mabel, Heir to Cragflame

Other Mice you control get +1/+1.
When Mabel, Heir to Cragflame enters, create Cragflame, a legendary colorless Equipment artifact token with "Equipped creature gets +1/+1 and has vigilance, trample, and haste" and equip {2}.

Skyclave Apparition

When Skyclave Apparition enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When Skyclave Apparition leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Arcane Signet

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

Rogue's Passage

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

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

Dawn's Truce

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
You and permanents you control gain hexproof until end of turn. If the gift was promised, permanents you control also gain indestructible until end of turn.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Aether Channeler

When Aether Channeler enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Long River's Pull

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Counter target creature spell. If the gift was promised, instead counter target spell.

Sundown Pass

Sundown Pass enters tapped unless you control two or more other lands.
{T}: Add {R} or {W}.

Echoing Assault

Creature tokens you control have menace.
Whenever you attack a player, choose target nontoken creature that's attacking that player. Create a token that's a copy of that creature, except it's 1/1. The token enters tapped and attacking that player. Sacrifice it at the beginning of the next end step.

Boros Signet

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Calamity of Cinders

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Calamity of Cinders deals 6 damage to each untapped creature.

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Counterspell

Shield Broker

When Shield Broker enters, put a shield counter on target noncommander creature you don't control. You gain control of that creature for as long as it has a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Combat Celebrant

If Combat Celebrant hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Overpowering Attack

Freerunning {2}{R} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Untap all creatures you control that attacked this turn. If it's your main phase, there is an additional combat phase after this phase, followed by an additional main phase.

Beza, the Bounding Spring

When Beza, the Bounding Spring enters, create a Treasure token if an opponent controls more lands than you. You gain 4 life if an opponent has more life than you. Create two 1/1 blue Fish creature tokens if an opponent controls more creatures than you. Draw a card if an opponent has more cards in hand than you.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Luminous Broodmoth

Flying
Whenever a creature you control without flying dies, return it to the battlefield under its owner's control with a flying counter on it.

Izzet Signet

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Plains

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Mystic Monastery

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

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Claim Jumper

Vigilance
When Claim Jumper enters, if an opponent controls more lands than you, you may search your library for a Plains card and put it onto the battlefield tapped. Then if an opponent controls more lands than you, repeat this process once. If you search your library this way, shuffle.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Splash Portal

Exile target creature you control, then return it to the battlefield under its owner's control. If that creature is a Bird, Frog, Otter, or Rat, draw a card.

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.)

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.

Selfless Spirit

Flying
Sacrifice Selfless Spirit: Creatures you control gain indestructible until end of turn.

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Angel of the Ruins

Flying
When Angel of the Ruins enters, exile up to two target artifacts and/or enchantments.
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Perch Protection

Gift an extra turn (You may promise an opponent a gift as you cast this spell. If you do, they take an extra turn after this one.)
Create four 2/2 blue Bird creature tokens with flying. If the gift was promised, all permanents you control phase out, and until your next turn, your life total can't change and you gain protection from everything.
Exile Perch Protection.

Thopter Engineer

When Thopter Engineer enters, create a 1/1 colorless Thopter artifact creature token with flying.
Artifact creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Nesting Dovehawk

Flying
At the beginning of combat on your turn, populate. (Create a token that's a copy of a creature token you control.)
Whenever a creature token you control enters, put a +1/+1 counter on Nesting Dovehawk.

Azorius Signet

Dazzling Denial

Counter target spell unless its controller pays {2}. If you control a Bird, counter that spell unless its controller pays {4} instead.

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. Talisman of Conviction deals 1 damage to you.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Blasphemous Act

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

Parting Gust

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Exile target nontoken creature. If the gift wasn't promised, return that card to the battlefield under its owner's control with a +1/+1 counter on it at the beginning of the next end step.

Ghostly Flicker

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

Excalibur, Sword of Eden

This spell costs {X} less to cast, where X is the total mana value of historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)
Equipped creature gets +10/+0 and has vigilance.
Equip legendary creature {2}

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Inferno Titan

{R}: Inferno Titan gets +1/+0 until end of turn.
Whenever Inferno Titan enters or attacks, it deals 3 damage divided as you choose among one, two, or three targets.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Rose Room Treasurer

Alliance — Whenever another creature you control enters, create a Treasure token if this is the first or second time this ability has resolved this turn. Otherwise, you may pay {X}. When you do, Rose Room Treasurer deals X damage to any target.

Murmuration

Birds you control get +1/+1 and have vigilance.
At the beginning of your end step, for each spell you've cast this turn, create a 1/2 blue Bird creature token with flying named Storm Crow.

Ornithopter of Paradise

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Spirited Companion

When Spirited Companion enters, draw a card.

Mountain

Arthur, Marigold Knight

Haste
Whenever Arthur, Marigold Knight and at least one other creature attack, look at the top six cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking. Put the rest on the bottom of your library in a random order. Return that creature to its owner's hand at end of combat.

Panharmonicon

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

Loyal Warhound

Vigilance
When Loyal Warhound enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Fortune Teller's Talent

(Gain the next level as a sorcery to add its ability.)
You may look at the top card of your library any time.
{3}{U}: Level 2
As long as you've cast a spell this turn, you may play cards from the top of your library.
{2}{U}: Level 3
Spells you cast from anywhere other than your hand cost {2} less to cast.

Sol Ring

Plumecreed Escort

Flash
Flying
When Plumecreed Escort enters, target creature you control gains hexproof until end of turn.

Stormcarved Coast

Stormcarved Coast enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Goblin Bombardment

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

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.

Stolen by the Fae

Return target creature with mana value X to its owner's hand. You create X 1/1 blue Faerie creature tokens with flying.

Warstorm Surge

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

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Dewdrop Cure

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Return up to two target creature cards each with mana value 2 or less from your graveyard to the battlefield. If the gift was promised, instead return up to three target creature cards each with mana value 2 or less from your graveyard to the battlefield.

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Impact Tremors

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

Island

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.