Jötun Owl Keeper

Cumulative upkeep {W} or {U} (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.)
When this creature dies, create a 1/1 white Bird creature token with flying for each age counter on it.

Soulcatcher

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

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.)

Counterspell

Kykar, Zephyr Awakener

Flying
Whenever you cast a noncreature spell, choose one —
• Exile another target creature you control. Return that card to the battlefield under its owner's control at the beginning of the next end step.
• Create a 1/1 white Spirit creature token with flying.

Skycloud Expanse

Command Tower

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

Arcanist's Owl

Flying
When this creature enters, look at the top four cards of your library. You may reveal an artifact or enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Floodfarm Verge

{T}: Add {W}.
{T}: Add {U}. Activate only if you control a Plains or an Island.

Judge's Familiar

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

Clinquant Skymage

Flying
Whenever you draw a card, put a +1/+1 counter on this creature.

Aven Interrupter

Flash
Flying
When this creature enters, exile target spell. It becomes plotted. (Its owner may cast it as a sorcery on a later turn without paying its mana cost.)
Spells your opponents cast from graveyards or from exile cost {2} more to cast.

Deluge

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.

Gustcloak Skirmisher

Flying
Whenever this creature becomes blocked, you may untap it and remove it from combat.

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Skyway Robber

Flying
Escape—{3}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
This creature escapes with "Whenever this creature deals combat damage to a player, you may cast an artifact, instant, or sorcery spell from among cards exiled with this creature without paying its mana cost."

Augury Owl

Flying
When this creature enters, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Eagles of the North

Flying
When this creature enters, creatures you control get +1/+0 and gain first strike until end of turn.
Plainscycling {1} ({1}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Esior, Wardwing Familiar

Flying
Spells your opponents cast that target one or more commanders you control cost {3} more to cast.
Partner (You can have two commanders if both have partner.)

Door of Destinies

As this artifact enters, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on this artifact.
Creatures you control of the chosen type get +1/+1 for each charge counter on this artifact.

Rally the Ranks

As this enchantment enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.

Evolving Wilds

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

Souvenir Snatcher

Mutate {5}{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, gain control of target noncreature artifact.

Airborne Aid

Draw a card for each Bird on the battlefield.

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, this creature connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Island

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Steel-Plume Marshal

Flying
Whenever this creature attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Prairie Stream

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

Emeria Angel

Flying
Landfall — Whenever a land you control enters, you may create a 1/1 white Bird creature token with flying.

Kangee, Aerie Keeper

Kicker {X}{2} (You may pay an additional {X}{2} as you cast this spell.)
Flying
When Kangee enters, if it was kicked, put X feather counters on it.
Other Bird creatures get +1/+1 for each feather counter on Kangee.

Kastral, the Windcrested

Flying
Whenever one or more Birds you control deal combat damage to a player, choose one —
• You may put a Bird creature card from your hand or graveyard onto the battlefield with a finality counter on it.
• Put a +1/+1 counter on each Bird you control.
• Draw a card.

Kenku Artificer

Homunculus Servant — When this creature enters, put three +1/+1 counters on up to one target noncreature artifact. That artifact becomes a 0/0 Homunculus artifact creature with flying.

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Curiosity Crafter

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

River Hoopoe

Flying
{3}{G}{U}: You gain 2 life and draw a card.

Blizzard Strix

Flash
Flying
When this creature enters, if you control another snow permanent, exile target permanent other than this creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Azorius Signet

Crookclaw Elder

Flying
Tap two untapped Birds you control: Draw a card.
Tap two untapped Wizards you control: Target creature gains flying until end of turn.

High Sentinels of Arashin

Flying
This creature gets +1/+1 for each other creature you control with a +1/+1 counter on it.
{3}{W}: Put a +1/+1 counter on target creature.

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Junk Diver

Flying
When this creature dies, return another target artifact card from your graveyard to your hand.

Owlbear Cub

Mama's Coming — Whenever this creature attacks a player who controls eight or more lands, look at the top eight cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking that player. Put the rest on the bottom of your library in a random order.

Swords to Plowshares

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

Screaming Swarm

Flying
Whenever you attack with one or more creatures, target player mills that many cards. (To mill a card, a player puts the top card of their library into their graveyard.)
{2}{U}: Put this card from your graveyard into your library second from the top.

Shrike Force

Murder of Crows

Flying
Whenever another creature dies, you may draw a card. If you do, discard a card.

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.)

Bronzebeak Moa

Whenever another creature you control enters, this creature gets +3/+3 until end of turn.

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Commander Eesha

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: This artifact becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Negate

Gwaihir, Greatest of the Eagles

Flying
Whenever Gwaihir attacks, target attacking creature gains flying until end of turn.
At the beginning of each end step, if you gained 3 or more life this turn, create a 3/3 white Bird creature token with flying and "Whenever this token attacks, target attacking creature gains flying until end of turn."

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Dazzling Denial

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

Plumecreed Escort

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

Gust of Wind

This spell costs {2} less to cast if you control a creature with flying.
Return target nonland permanent you don't control to its owner's hand.
Draw a card.

Battlefield Raptor

Thriving Isle

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

Stormscape Familiar

Flying
White spells and black spells you cast cost {1} less to cast.

Scour the Desert

Exile target creature card from your graveyard. Create X 1/1 white Bird creature tokens with flying, where X is the exiled card's toughness.

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.

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.

Aven Brigadier

Flying
Other Bird creatures get +1/+1.
Other Soldier creatures get +1/+1.

Favorable Winds

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

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.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Glarecaster

Flying
{5}{W}: The next time damage would be dealt to this creature and/or you this turn, that damage is dealt to any target instead.

Harrier Strix

Flying
When this creature enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

Restless Anchorage

This land enters tapped.
{T}: Add {W} or {U}.
{1}{W}{U}: Until end of turn, this land becomes a 2/3 white and blue Bird creature with flying. It's still a land.
Whenever this land attacks, create a Map token.

Shabraz, the Skyshark

Partner with Brallin, Skyshark Rider
Flying
Whenever you draw a card, put a +1/+1 counter on Shabraz and you gain 1 life.
{W/U}: Target Human gains flying until end of turn.

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.

Alrund's Epiphany

Create two 1/1 blue Bird creature tokens with flying. Take an extra turn after this one. Exile Alrund's Epiphany.
Foretell {4}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Tainted Observer

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever another creature you control enters, you may pay {2}. If you do, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ishai, Ojutai Dragonspeaker

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Ishai.
Partner (You can have two commanders if both have partner.)

Kangee, Sky Warden

Flying, vigilance
Whenever Kangee attacks, attacking creatures with flying get +2/+0 until end of turn.
Whenever Kangee blocks, blocking creatures with flying get +0/+2 until end of turn.

Senu, Keen-Eyed Protector

Flying, vigilance
{T}, Exile Senu: You gain 2 life and scry 2.
When a legendary creature you control attacks and isn't blocked, if this card is exiled, put it onto the battlefield attacking.

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 this creature.

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Skymark Roc

Flying
Whenever this creature attacks, you may return target creature defending player controls with toughness 2 or less to its owner's hand.

Windbrisk Raptor

Flying
Attacking creatures you control have lifelink.

Celestial Gatekeeper

Flying
When this creature dies, exile it, then return up to two target Bird and/or Cleric permanent cards from your graveyard to the battlefield.

Silver Raven

Flying
When this creature enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Courier Hawk

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Mist Raven

Flying
When this creature enters, return target creature to its owner's hand.

Aven Cloudchaser

Flying (This creature can't be blocked except by creatures with flying or reach.)
When this creature enters, destroy target enchantment.

Cloudfin Raptor

Flying
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.)

Koilos Roc

Flash
Flying
When this creature enters, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Knightfisher

Flying
Whenever another nontoken Bird you control enters, create a 1/1 blue Fish creature token.

Aven Gagglemaster

Flying
When this creature enters, you gain 2 life for each creature you control with flying.

Gustcloak Savior

Flying
Whenever a creature you control becomes blocked, you may untap that creature and remove it from combat.

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}.

Kangee's Lieutenant

Flying
Whenever this creature attacks, attacking creatures with flying get +1/+1 until end of turn.
Encore {5}{W} ({5}{W}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Icon of Ancestry

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Battle Screech

Create two 1/1 white Bird creature tokens with flying.
Flashback—Tap three untapped white creatures you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Spire Owl

Flying
When this creature enters, look at the top four cards of your library, then put them back in any order.

Gwaihir the Windlord

This spell costs {2} less to cast as long as you've drawn two or more cards this turn.
Flying, vigilance
Other Birds you control have vigilance.