Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Loyal Pegasus

Flying
This creature can't attack or block alone.

Keleth, Sunmane Familiar

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Loyal Unicorn

Vigilance
Lieutenant — At the beginning of combat on your turn, if you control your commander, prevent all combat damage that would be dealt to creatures you control this turn. Other creatures you control gain vigilance until end of turn.

Inspiring Unicorn

Whenever this creature attacks, creatures you control get +1/+1 until end of turn.

Regal Bunnicorn

Regal Bunnicorn's power and toughness are each equal to the number of nonland permanents you control.

Akroan Horse

Defender
When this creature enters, an opponent gains control of it.
At the beginning of your upkeep, each opponent creates a 1/1 white Soldier creature token.

Ronom Unicorn

Sacrifice this creature: Destroy target enchantment.

Pegasus Courser

Flying
Whenever this creature attacks, another target attacking creature gains flying until end of turn.

Rescue the Foal

Exile target creature you control, then return that card to the battlefield under its owner's control. (Then exile this card. You may cast the creature later from exile.)

Pegasus Guardian

Flying
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, create a 1/1 white Pegasus creature token with flying.

Pegasus Guardian // Rescue the Foal

Bill the Pony

When Bill the Pony enters, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Sacrifice a Food: Until end of turn, target creature you control assigns combat damage equal to its toughness rather than its power.

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Splendor Mare

Lifelink
Cycling {1}{W} ({1}{W}, Discard this card: Draw a card.)
When you cycle this card, put a lifelink counter on target creature you control.

Crested Sunmare

Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.

Nyxborn Unicorn

Bestow {3}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Enchanted creature gets +2/+2 and has mentor.

Opaline Unicorn

Mesa Unicorn

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

Steadfast Unicorn

{3}{W}: Creatures you control get +1/+1 and gain vigilance until end of turn. Activate only during your turn. (Attacking doesn't cause them to tap.)

Wishmonger

{2}: Target creature gains protection from the color of its controller's choice until end of turn. Any player may activate this ability.

Plated Pegasus

Flash (You may cast this spell any time you could cast an instant.)
Flying
If a spell would deal damage to a permanent or player, prevent 1 damage that spell would deal to that permanent or player.

Boreas Charger

Flying
When this creature leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.

Revered Unicorn

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When this creature leaves the battlefield, you gain life equal to the number of age counters on it.

Diamond Mare

As this creature enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.