Aven Courier

Flying
Whenever Aven Courier attacks, choose a counter on a permanent you control. Put a counter of that kind on target permanent you control if it doesn't have a counter of that kind on it.

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Warden of Evos Isle

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

Owlbear Cub

Mama's Coming — Whenever Owlbear Cub attacks a player who controls eight or more lands, look at the top eight cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking that player. Put the rest on the bottom of your library in a random order.

Thieving Magpie

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Thieving Magpie deals damage to an opponent, draw a card.

Birds of Paradise

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, Ledger Shredder connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Dream Thrush

Flying
{T}: Target land becomes the basic land type of your choice until end of turn.

Gilded Goose

Flying
When Gilded Goose enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{1}{G}, {T}: Create a Food token.
{T}, Sacrifice a Food: Add one mana of any color.

Preening Champion

Flying
When Preening Champion enters, create a 1/1 blue and red Elemental creature token.

Whippoorwill

{G}{G}, {T}: Target creature can't be regenerated this turn. Damage that would be dealt to that creature this turn can't be prevented or dealt instead to another permanent or player. When the creature dies this turn, exile the creature.

Messenger Jays

Flying
Council's dilemma — When Messenger Jays enters, starting with you, each player votes for feather or quill. Put a +1/+1 counter on Messenger Jays for each feather vote and draw a card for each quill vote. For each card drawn this way, discard a card.

Ithilien Kingfisher

Flying
When Ithilien Kingfisher dies, draw a card.

River Hoopoe

Flying
{3}{G}{U}: You gain 2 life and draw a card.

The Goose Mother

Flying
The Goose Mother enters with X +1/+1 counters on it.
When The Goose Mother enters, create half X Food tokens, rounded up.
Whenever The Goose Mother attacks, you may sacrifice a Food. If you do, draw a card.