Air Servant

Flying
{2}{U}: Tap target creature with flying.

Arborea Pegasus

Flying
When Arborea Pegasus enters the battlefield, target creature gets +1/+1 and gains flying until end of turn.

Aeromoeba

Flying
Discard a card: Switch Aeromoeba's power and toughness until end of turn.

Aether Meltdown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature or Vehicle
When Aether Meltdown enters the battlefield, you get {E}{E} (two energy counters).
Enchanted creature gets -4/-0.

Air Elemental

Aetherplasm

Whenever Aetherplasm blocks a creature, you may return Aetherplasm to its owner's hand. If you do, you may put a creature card from your hand onto the battlefield blocking that creature.

Aether Figment

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Aether Figment can't be blocked.
If Aether Figment was kicked, it enters the battlefield with two +1/+1 counters on it.

Angelic Cub

Whenever Angelic Cub becomes the target of a spell or ability for the first time each turn, put a +1/+1 counter on it.
As long as Angelic Cub has three or more +1/+1 counters on it, it has flying.

Air-Cult Elemental

Flying
Whirlwind — When Air-Cult Elemental enters the battlefield, return up to one other target creature to its owner's hand.