Thought Vessel

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

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.

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.

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.

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.

Island

Make Your Move

Destroy target artifact, enchantment, or creature with power 4 or greater.

Eaten by Piranhas

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature loses all abilities and is a black Skeleton creature with base power and toughness 1/1. (It loses all other colors, card types, and creature types.)

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.)

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.)

Lifecreed Duo

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

Urza's Cave

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

Aerie Auxiliary

Flying
When this creature enters, support 2. (Put a +1/+1 counter on each of up to two other target creatures.)

Thrummingbird

Flying
Whenever this creature 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.)

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.)

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

No More Lies

Counter target spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Landroval, Horizon Witness

Flying
Whenever two or more creatures you control attack a player, target attacking creature without flying gains flying until end of turn.

Wingmate Roc

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

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.)

Plumecreed Escort

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

Marble Diamond

This artifact enters tapped.
{T}: Add {W}.

Harrier Strix

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

Requisition Raid

Spree (Choose one or more additional costs.)
+ {1} — Destroy target artifact.
+ {1} — Destroy target enchantment.
+ {1} — Put a +1/+1 counter on each creature target player controls.

Dazzling Denial

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

Healer's Hawk

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

Jackdaw Savior

Flying
Whenever this creature or another creature you control with flying dies, return another target creature card with lesser mana value from your graveyard to the battlefield.

Sol Ring

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.)

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.

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.

Jubilant Skybonder

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

Haystack

{2}, {T}: Target creature you control phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)

Plains

Thunderclap Wyvern

Flash (You may cast this spell any time you could cast an instant.)
Flying
Other creatures you control with flying get +1/+1.

Aetherize

Return all attacking creatures to their owner's hand.

Echo Inspector

Flying
When this creature enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Swooping Protector

Flash
Flying
This creature enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Empyrean Eagle

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

Lilypad Village

{T}: Add {C}.
{T}: Add {U}. Spend this mana only to cast a creature spell.
{U}, {T}: Surveil 2. Activate only if a Bird, Frog, Otter, or Rat entered the battlefield under your control this turn.

Disperse

Return target nonland permanent to its owner's hand.

Repel Calamity

Destroy target creature with power or toughness 4 or greater.

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.

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.

Knightfisher

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

Mockingbird

Flying
You may have this creature 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 this creature, except it's a Bird in addition to its other types and it has flying.

Skycat Sovereign

Flying
This creature 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.

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.

Traveler's Amulet

{1}, Sacrifice this artifact: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Pileated Provisioner

Flying
When this creature enters, put a +1/+1 counter on target creature you control without flying.

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.

Mystical Tether

You may cast this spell as though it had flash if you pay {2} more to cast it.
When this enchantment enters, exile target artifact or creature an opponent controls until this enchantment leaves the battlefield.

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

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.

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.

Seized from Slumber

This spell costs {3} less to cast if it targets a tapped creature.
Destroy target 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.

Salvation Swan

Flash
Flying
Whenever this creature or another Bird you control enters, exile up to one target creature you control without flying. Return it to the battlefield under its owner's control with a flying counter on it at the beginning of the next end step.

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.)

Revoke Existence

Rescue

Return target permanent you control to its owner's hand.

Crumb and Get It

Gift a Food (You may promise an opponent a gift as you cast this spell. If you do, they create a Food token before its other effects. It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Target creature you control gets +2/+2 until end of turn. If the gift was promised, that creature also gains indestructible until end of turn.

Day of Judgment

Coastal Piracy

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

Meneldor, Swift Savior

Flying
Whenever Meneldor deals combat damage to a player, exile up to one target creature you own, then return it to the battlefield under your control.

Shrike Force

Serra Disciple

Flying, first strike
Whenever you cast a historic spell, this creature gets +1/+1 until end of turn. (Artifacts, legendaries, and Sagas are historic.)