Aven Envoy

Duskrider Falcon

Freewind Falcon

Cloudfin Raptor

Flying
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Healer's Hawk

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

Courier Hawk

Royal Falcon

Rustwing Falcon

Battlefield Raptor

Suntail Hawk

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.

Aven Skirmisher

Skyshroud Falcon

Sea Eagle

Colorful Feiyi Sparrow

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