Valorous Steed

Vigilance (Attacking doesn't cause this creature to tap.)
When Valorous Steed enters the battlefield, create a 2/2 white Knight creature token with vigilance.

Good-Fortune Unicorn

Whenever another creature enters the battlefield under your control, put a +1/+1 counter on that creature.

Steadfast Unicorn

{3}{W}: Creatures you control get +1/+1 and gain vigilance until end of turn. Activate only during your turn.

Brightmare

When Brightmare enters the battlefield, tap up to one target creature. You gain life equal to that creature's power.

Seraphic Steed

First strike, lifelink
Whenever Seraphic Steed attacks while saddled, create a 3/3 white Angel creature token with flying.
Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

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.

Daybreak Charger

When Daybreak Charger enters the battlefield, target creature gets +2/+0 until end of turn.

Wishmonger

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

Majestic Auricorn

Mutate {3}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Vigilance
Whenever this creature mutates, you gain 4 life.

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.

Zebra Unicorn

Whenever Zebra Unicorn deals damage, you gain that much life.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Ronom Unicorn

Sacrifice Ronom Unicorn: Destroy target enchantment.

Captivating Unicorn

Constellation — Whenever an enchantment enters the battlefield under your control, tap target creature an opponent controls.

Capashen Unicorn

{1}{W}, {T}, Sacrifice Capashen Unicorn: Destroy target artifact or enchantment.

Opaline Unicorn

Mesa Unicorn

Regal Unicorn

Benevolent Unicorn

If a spell would deal damage to a permanent or player, it deals that much damage minus 1 to that permanent or player instead.

Noble Quarry

Bestow {5}{G} (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 to a creature.)
All creatures able to block Noble Quarry or enchanted creature do so.
Enchanted creature gets +1/+1.

Prized Unicorn

All creatures able to block Prized Unicorn do so.

Regal Bunnicorn

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

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 Revered Unicorn leaves the battlefield, you gain life equal to the number of age counters on it.

Neighborhood Guardian

Whenever another creature with power 2 or less enters the battlefield under your control, target creature you control gets +1/+1 until end of turn.

Pearled Unicorn

Emiel the Blessed

{3}: Exile another target creature you control, then return it to the battlefield under its owner's control.
Whenever another creature enters the battlefield under your control, you may pay {G/W}. If you do, put a +1/+1 counter on it. If it's a Unicorn, put two +1/+1 counters on it instead. ({G/W} can be paid with either {G} or {W}.)

Inspiring Unicorn

Whenever Inspiring Unicorn attacks, creatures you control get +1/+1 until end of turn.

Splendor Mare

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

Rider in Need

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the creature later from exile.)