Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Breath of Life

Return target creature card from your graveyard to the battlefield.

Warden of Evos Isle

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

Aven Skirmisher

Aven Warhawk

Amplify 1 (As this creature enters, put a +1/+1 counter on it for each Bird and/or Soldier card you reveal in your hand.)
Flying

Apex Hawks

Multikicker {1}{W} (You may pay an additional {1}{W} any number of times as you cast this spell.)
Flying
This creature enters with a +1/+1 counter on it for each time it was kicked.

Shriek Raptor

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

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.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever this Equipment becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

False Defeat

Cloudreach Cavalry

As long as you control a Bird, this creature gets +2/+2 and has flying.

Empowered Autogenerator

This artifact enters tapped.
{T}: Put a charge counter on this artifact. Add X mana of any one color, where X is the number of charge counters on this artifact.

Abzan Skycaptain

Flying
When this creature dies, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.)

Emeria, the Sky Ruin

This land enters tapped.
At the beginning of your upkeep, if you control seven or more Plains, you may return target creature card from your graveyard to the battlefield.
{T}: Add {W}.

Astral Cornucopia

This artifact enters with X charge counters on it.
{T}: Choose a color. Add one mana of that color for each charge counter on this artifact.

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever this creature becomes blocked, it gets +2/+2 until end of turn.

Aven Brigadier

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

Island

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.)

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Spire Owl

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

Tah-Crop Elite

Flying
You may exert this creature as it attacks. When you do, creatures you control get +1/+1 until end of turn. (An exerted creature won't untap during your next untap step.)

Supply-Line Cranes

Flying
When this creature enters, put a +1/+1 counter on target creature.

Tine Shrike

Steady Progress

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Soulcatcher

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

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.)

Miraculous Recovery

Return target creature card from your graveyard to the battlefield. Put a +1/+1 counter on it.

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.)

Coretapper

{T}: Put a charge counter on target artifact.
Sacrifice this creature: Put two charge counters on target artifact.

Resurrection

Contentious Plan

Plains

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.)

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.

Dawnfeather Eagle

Flying
When this creature enters, creatures you control get +1/+1 and gain vigilance until end of turn.

Storm Crow

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

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.

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

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.

Glint-Nest Crane

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

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.)

Armory of Iroas

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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.

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.