Mockingbird

Flying
You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

Arcane Signet

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

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Aven Brigadier

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

Aven Mimeomancer

Flying
At the beginning of your upkeep, you may put a feather counter on target creature. If you do, that creature has base power and toughness 3/1 and has flying for as long as it has a feather counter on it.

Keeper of the Nine Gales

Flying
{T}, Tap two untapped Birds you control: Return target permanent to its owner's hand.

Soulcatchers' Aerie

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

Emeria Angel

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

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Rogue's Passage

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

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

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.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Curiosity Crafter

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

Raise the Palisade

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

Gustcloak Savior

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

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Commander Eesha

Magus of the Moat

Rally of Wings

Untap all creatures you control. Creatures you control with flying get +2/+2 until end of turn.

True Conviction

Creatures you control have double strike and lifelink.

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.)

Windbrisk Raptor

Flying
Attacking creatures you control have lifelink.

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.)

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Cartographer's Hawk

Flying
When Cartographer's Hawk 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.

Sejiri Refuge

Sejiri Refuge enters tapped.
When Sejiri Refuge enters, you gain 1 life.
{T}: Add {W} or {U}.

Celestial Gatekeeper

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

Ishai, Ojutai Dragonspeaker

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

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Tranquil Cove

Tranquil Cove enters tapped.
When Tranquil Cove enters, you gain 1 life.
{T}: Add {W} or {U}.

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 creature attacks, target attacking creature gains flying until end of turn."

Gravitational Shift

Creatures with flying get +2/+0.
Creatures without flying get -2/-0.

Coastal Piracy

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

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Azorius Guildgate

Azorius Guildgate enters tapped.
{T}: Add {W} or {U}.

Azorius Signet

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

Nimble Obstructionist

Flash
Flying
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)
When you cycle Nimble Obstructionist, counter target activated or triggered ability you don't control.

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.)

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Airborne Aid

Draw a card for each Bird on the battlefield.

Wingmate Roc

Flying
Raid — When Wingmate Roc enters, if you attacked this turn, create a 3/4 white Bird creature token with flying.
Whenever Wingmate Roc attacks, you gain 1 life for each attacking creature.

Favorable Winds

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

Citadel Gate

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

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.)

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

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.

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.)

Deluge

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Aerial Assault

Destroy target tapped creature. You gain 1 life for each creature you control with flying.

Aetherize

Return all attacking creatures to their owner's hand.

Aerial Extortionist

Flying
Whenever Aerial Extortionist enters or deals combat damage to a player, exile up to one target nonland permanent. For as long as that card remains exiled, its owner may cast it.
Whenever another player casts a spell from anywhere other than their hand, draw a card.

Scouting Hawk

Flying
Keen Sight — When Scouting Hawk 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.

Skycat Sovereign

Flying
Skycat Sovereign gets +1/+1 for each other creature you control with flying.
{2}{W}{U}: Create a 1/1 white Cat Bird creature token with flying.

The Key to the Vault

Whenever equipped creature deals combat damage to a player, look at that many cards from the top of your library. You may exile a nonland card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.
Equip {2}{U}

Healer's Hawk

Battlefield Raptor

Dovescape

({W/U} can be paid with either {W} or {U}.)
Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value.

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.)

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Island

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature you control with flying enters, Watcher of the Spheres gets +1/+1 until end of turn.

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.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Reliquary Tower

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

Disenchant

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.

Soulcatcher

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

Eagle of Deliverance

Flying
When Eagle of Deliverance enters, put an indestructible counter on another target creature you control. Draw a card if that creature's power is 2 or less.

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Commander's Sphere

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

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Temple of Enlightenment

Temple of Enlightenment enters tapped.
When Temple of Enlightenment enters, scry 1.
{T}: Add {W} or {U}.

Render Silent

Counter target spell. Its controller can't cast spells this turn.

Glacial Floodplain

({T}: Add {W} or {U}.)
Glacial Floodplain enters tapped.

Skybridge Towers

Skybridge Towers enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice Skybridge Towers: Draw a card.

Kangee, Aerie Keeper

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

Cloudchaser Kestrel

Flying
When Cloudchaser Kestrel enters, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Plains

Counterspell

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Prairie Stream

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

Shabraz, the Skyshark

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