Inspired -- Whenever Aerie Worshippers becomes untapped, you may pay {2}{U}. If you do, create a 2/2 blue Bird enchantment creature token with flying.

Defender (This creature can't attack.)

Flying

When Ageless Sentinels blocks, it becomes a Bird Giant, and it loses defender. (It's no longer a Wall. This effect lasts indefinitely.)

Draw a card for each Bird on the battlefield.

{T}: Add {C}.

{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

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

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.

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.)

{T}: Add {W} or {U}.

{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

{1}, {T}: Add {W}{U}.

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.)

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.

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.

Whenever another permanent you control becomes the target of a spell or ability an opponent controls, you may return that permanent to its owner's hand.

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

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

Sacrifice Commander's Sphere: Draw a card.

Flying

You have no maximum hand size.

Whenever a creature token you control deals combat damage to a player, draw a card.

Flying

Landfall -- Whenever a land enters the battlefield under your control, you may create a 1/1 white Bird creature token with flying.

Flying

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

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

{T}: Add one mana of any color that a land an opponent controls could produce.

Create a 1/1 white Bird creature token with flying, then populate. (Create a token that's a copy of a creature token you control.)

Whenever Falconer Adept attacks, create a 1/1 white Bird creature token with flying that's tapped and attacking.

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

{T}: Add one mana of any color that a land an opponent controls could produce.

Defender, flying

Prevent all combat damage that would be dealt to and dealt by Fog Bank.

If it's not your turn, you may exile a white card from your hand rather than pay this spell's mana cost.

Flash

Creatures you control get +1/+1.

({T}: Add {W} or {U}.)

Glacial Floodplain enters the battlefield tapped.

Creatures with flying get +2/+0.

Creatures without flying get -2/-0.

Flying

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

Flying, lifelink

As Icon of Ancestry enters the battlefield, 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.

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

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

Flying

Creatures you control with flying have "Spells your opponents cast that target this creature cost {2} more to cast."

Flying

Sacrifice Judge's Familiar: Counter target instant or sorcery spell unless its controller pays {1}.

Flying

Whenever Kangee's Lieutenant 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.)

Flying, vigilance

Whenever Kangee, Sky Warden 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.

Flying

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

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

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)

I -- You and target opponent each draw two cards.

II -- Create a 1/1 white Bird creature token with flying.

III -- Put a +1/+1 counter on each of up to two target creatures.

Flying

Council's dilemma -- When Messenger Jays enters the battlefield, starting with you, each player votes for feather or quill. Put a +1/+1 counter on Messenger Jays for each feather vote and draw a card for each quill vote. For each card drawn this way, discard a card.

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.)

Defender, flying

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

+1: Until your next turn, up to one target creature gets -5/-0.

-3: Return up to two target creatures to their owners' hands.

-7: Creatures you control with flying get +5/+5 until end of turn.

+2: Until your next turn, up to one target creature gets -2/-0 and loses flying.

-3: Create a 4/4 blue Elemental Bird creature token with flying.

-8: You get an emblem with "Islands you control have '{T}: Draw a card.'"

Flying

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

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

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 enters the battlefield under your control, put a +1/+1 counter on Nesting Dovehawk.

Flying

Tribute 2 (As this creature enters the battlefield, an opponent of your choice may put two +1/+1 counters on it.)

When Ornitharch enters the battlefield, if tribute wasn't paid, create two 1/1 white Bird creature tokens with flying.

Path of Ancestry enters the battlefield tapped.

{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

Flash

Defender, flying

As Port Town enters the battlefield, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters the battlefield tapped.

{T}: Add {W} or {U}.

({T}: Add {W} or {U}.)

Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

Flying

Pride of the Clouds gets +1/+1 for each other creature with flying on the battlefield.

Forecast -- {2}{W}{U}, Reveal Pride of the Clouds from your hand: Create a 1/1 white and blue Bird creature token with flying. (Activate only during your upkeep and only once each turn.)

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

Defender (This creature can't attack.)

When Roc Egg dies, create a 3/3 white Bird creature token with flying.

{T}: Add {C}.

{W}{U}, {T}, Sacrifice a Bird: Draw a card.

Sejiri Refuge enters the battlefield tapped.

When Sejiri Refuge enters the battlefield, you gain 1 life.

{T}: Add {W} or {U}.

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.)

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.

{1}, {T}: Add {W}{U}.

{T}: Add {C}{C}.

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.

Flying

Whenever Steel-Plume Marshal attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Flying

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

{T}: Add {C}.

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

Temple of Enlightenment enters the battlefield tapped.

When Temple of Enlightenment enters the battlefield, scry 1.

{T}: Add {W} or {U}.

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

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)

I -- Create a 1/1 blue Bird creature token with flying. You gain 2 life.

II -- Whenever one or more creatures you control with flying deal combat damage to a player this turn, look at that player's hand and draw a card.

III -- You may put a card you own from outside the game on top of your library.

Flying (This creature can't be blocked except by creatures with flying or reach.)

Whenever Thieving Magpie deals damage to an opponent, draw a card.

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.)

Tranquil Cove enters the battlefield tapped.

When Tranquil Cove enters the battlefield, you gain 1 life.

{T}: Add {W} or {U}.

Defender, flying (This creature can't attack, and it can block creatures with flying.)

Flying

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

Flying

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

Whenever another creature with flying enters the battlefield under your control, Watcher of the Spheres gets +1/+1 until end of turn.

Flying

Attacking creatures you control have lifelink.

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

Draw two cards.

Flying

Raid -- When Wingmate Roc enters the battlefield, 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.

When Wingspan Mentor enters the battlefield, put a flying counter on target non-Human creature you control.

{2}{U}, {T}: Put a +1/+1 counter on each creature you control with flying.