Salvation Swan

Flash
Flying
Whenever Salvation Swan 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.

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.

Dazzling Denial

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

Lifecreed Duo

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

Builder's Talent

(Gain the next level as a sorcery to add its ability.)
When Builder's Talent enters, create a 0/4 white Wall creature token with defender.
{W}: Level 2
Whenever one or more noncreature, nonland permanents you control enter, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target noncreature, nonland permanent card from your graveyard to the battlefield.

Splash Portal

Exile target creature you control, then return it to the battlefield under its owner's control. If that creature is a Bird, Frog, Otter, or Rat, draw a card.

Brightblade Stoat

Valley Questcaller

Whenever one or more other Rabbits, Bats, Birds, and/or Mice you control enter, scry 1.
Other Rabbits, Bats, Birds, and Mice you control get +1/+1.

Plumecreed Mentor

Flying
Whenever Plumecreed Mentor or another creature you control with flying enters, put a +1/+1 counter on target creature you control without flying.

Shrike Force

Finch Formation

Offspring {3} (You may pay an additional {3} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
When this creature enters, target creature you control gains flying until end of turn.

Knightfisher

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

Seedpod Squire

Flying
Whenever Seedpod Squire attacks, target creature you control without flying gets +1/+1 until end of turn.

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Plumecreed Escort

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

Jackdaw Savior

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

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.)

Island

Plains

Mouse Trapper

Flash
Valiant — Whenever Mouse Trapper becomes the target of a spell or ability you control for the first time each turn, tap target creature an opponent controls.

Pileated Provisioner

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