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.

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

Lifecreed Duo

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

Plumecreed Escort

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

Helga, Skittish Seer

Whenever you cast a creature spell with mana value 4 or greater, you draw a card, gain 1 life, and put a +1/+1 counter on Helga, Skittish Seer.
{T}: Add X mana of any one color, where X is Helga, Skittish Seer's power. Spend this mana only to cast creature spells with mana value 4 or greater or creature spells with {X} in their mana costs.

Byrke, Long Ear of the Law

Vigilance
When Byrke, Long Ear of the Law enters, put a +1/+1 counter on each of up to two target creatures.
Whenever a creature you control with a +1/+1 counter on it attacks, double the number of +1/+1 counters on it.

Pileated Provisioner

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

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.

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.