Zinnia, Valley's Voice

Flying
Zinnia gets +X/+0, where X is the number of other creatures you control with base power 1.
Creature spells you cast have offspring {2}. (You may pay an additional {2} as you cast a creature spell. If you do, when that creature enters, create a 1/1 token copy of it.)

Migratory Route

Create four 1/1 white Bird creature tokens with flying.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Perilous Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Island, Mountain, or Plains card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{R}{W} ({U}{R}{W}, Discard this card: Draw a card.)

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Distinguished Conjurer

Whenever another creature you control enters, you gain 1 life.
{4}{W}, {T}: Exile another target creature you control, then return it to the battlefield under its owner's control.

Sword of the Squeak

Equipped creature gets +1/+1 for each creature you control with base power or toughness 1.
Whenever a Hamster, Mouse, Rat, or Squirrel you control enters, you may attach this Equipment to that creature.
Equip {2}

Mountain

Thopter Engineer

When this creature 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.)

Aven Wind Guide

Flying, vigilance
Creature tokens you control have flying and vigilance.
Embalm {4}{W}{U} ({4}{W}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Bird Warrior with no mana cost. Embalm only as a sorcery.)

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.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Island

Soulcatchers' Aerie

Whenever a Bird is put into your graveyard from the battlefield, put a feather counter on this enchantment.
Bird creatures get +1/+1 for each feather counter on this enchantment.

Aspiring Aeronaut

Flying (This creature can't be blocked except by creatures with flying or reach.)
When this creature enters, create a 1/1 colorless Thopter artifact creature token with flying.

Augur of Bolas

When this creature enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Lifecreed Duo

Flying
Whenever another creature you control enters, you gain 1 life.

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Aven Sunstriker

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
Megamorph {4}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Impact Tremors

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

Reverent Hoplite

When this creature enters, create a number of 1/1 white Human Soldier creature tokens equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

Panharmonicon

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

Soulcatcher

Flying
Whenever a creature with flying dies, put a +1/+1 counter on this creature.

Anointer Priest

Whenever a creature token you control enters, you gain 1 life.
Embalm {3}{W} ({3}{W}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Human Cleric with no mana cost. Embalm only as a sorcery.)

Hanged Executioner

Flying
When this creature enters, create a 1/1 white Spirit creature token with flying.
{3}{W}, Exile this creature: Exile target creature.

Deputy of Detention

When this creature enters, exile target nonland permanent an opponent controls and all other nonland permanents that player controls with the same name as that permanent until this creature leaves the battlefield.

Kor Celebrant

Whenever this creature or another creature you control enters, you gain 1 life.

Aviation Pioneer

When this creature enters, create a 1/1 colorless Thopter artifact creature token with flying.

Seller of Songbirds

When this creature enters, create a 1/1 white Bird creature token with flying.

Airborne Aid

Draw a card for each Bird on the battlefield.

Evangel of Heliod

When this creature enters, create a number of 1/1 white Soldier creature tokens equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Mystic Monastery

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

Heliod's Pilgrim

When this creature enters, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle.

Sky Crier

Flying, lifelink
{3}{W}: You and target opponent each draw a card.

Tome Raider

Flying
When this creature enters, draw a card.

Evolving Wilds

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

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Mindshrieker

Flying
{2}: Target player mills a card. This creature gets +X/+X until end of turn, where X is the milled card's mana value.

Command Tower

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

Shrike Force

Judge's Familiar

Flying
Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {1}.

Plains

Scouting Hawk

Flying
Keen Sight — When this creature 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.

Storm of Souls

Return all creature cards from your graveyard to the battlefield. Each of them is a 1/1 Spirit with flying in addition to its other types. Exile Storm of Souls.

Pilgrim's Eye

Flying
When this creature enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Resolute Reinforcements

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, create a 1/1 white Soldier creature token.

Stormwild Capridor

Flying
If noncombat damage would be dealt to this creature, prevent that damage. Put a +1/+1 counter on this creature for each 1 damage prevented this way.

Battlefield Raptor

Thieving Magpie

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever this creature deals damage to an opponent, draw a card.

Chrome Courier

Flying
When this creature enters, reveal the top two cards of your library. Put one of them into your hand and the other into your graveyard. If you put an artifact card into your hand this way, you gain 3 life.

Skittering Surveyor

When this creature enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Favorable Winds

Creatures you control with flying get +1/+1.

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Tetsuko Umezawa, Fugitive

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

Cartographer's Hawk

Flying
When this creature deals combat damage to a player who controls more lands than you, return it to its owner's hand. If you do, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Brinebound Gift

Enchant creature
Whenever Brinebound Gift enters or enchanted creature becomes the target of an Aura spell, create a 1/1 white Spirit creature token with flying.
If Brinebound Gift would be put into a graveyard from anywhere, exile it instead.

Brine Comber

Whenever Brine Comber enters or becomes the target of an Aura spell, create a 1/1 white Spirit creature token with flying.
Disturb {W}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Brine Comber // Brinebound Gift

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Coveted Falcon

Flying
Whenever this creature attacks, gain control of target permanent you own but don't control.
Disguise {1}{U}
When this creature is turned face up, target opponent gains control of any number of target permanents you control. Draw a card for each one they gained control of this way.

Terramorphic Expanse

Akim, the Soaring Wind

Flying
Whenever you create one or more tokens for the first time each turn, create a 1/1 white Bird creature token with flying.
{3}{U}{R}{W}: Creature tokens you control gain double strike until end of turn.

Temple of Triumph

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {W}.

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.