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.

Centaur Courser

Nessian Courser

Loyal Pegasus

Flying
Loyal Pegasus can't attack or block alone.

Nylea's Disciple

When Nylea's Disciple enters the battlefield, you gain life equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Nylea's Huntmaster

When Nylea's Huntmaster enters the battlefield, target creature you control gets +X/+0 until end of turn, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Forest

Sungrace Pegasus

Flying (This creature can't be blocked except by creatures with flying or reach.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Chronicler of Heroes

When Chronicler of Heroes enters the battlefield, draw a card if you control a creature with a +1/+1 counter on it.

Inspiring Unicorn

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

Nyx Herald

At the beginning of combat on your turn, target enchanted creature or enchantment creature you control gets +1/+1 and gains trample until end of turn.

Lagonna-Band Storyteller

When Lagonna-Band Storyteller enters the battlefield, you may put target enchantment card from your graveyard on top of your library. If you do, you gain life equal to its mana value.

Zebra Unicorn

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

Lagonna-Band Elder

When Lagonna-Band Elder enters the battlefield, if you control an enchantment, you gain 3 life.

Purity

Flying
If noncombat damage would be dealt to you, prevent that damage. You gain life equal to the damage prevented this way.
When Purity is put into a graveyard from anywhere, shuffle it into its owner's library.

Rhox Faithmender

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
If you would gain life, you gain twice that much life instead.

Good-Fortune Unicorn

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

Pegasus Courser

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

Plains

Herald of the Pantheon

Enchantment spells you cast cost {1} less to cast.
Whenever you cast an enchantment spell, you gain 1 life.

Impassioned Orator

Whenever another creature enters the battlefield under your control, you gain 1 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.

Seton's Scout

Reach (This creature can block creatures with flying.)
Threshold — Seton's Scout gets +2/+2 as long as seven or more cards are in your graveyard.

Ajani's Welcome

Whenever a creature enters the battlefield under your control, you gain 1 life.

Lagonna-Band Trailblazer

Heroic — Whenever you cast a spell that targets Lagonna-Band Trailblazer, put a +1/+1 counter on Lagonna-Band Trailblazer.

Ronom Unicorn

Sacrifice Ronom Unicorn: Destroy target enchantment.

Rosemane Centaur

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Vigilance

Stormfront Pegasus

Nyxborn Courser

Centaur Safeguard

({G/W} can be paid with either {G} or {W}.)
When Centaur Safeguard dies, you may gain 3 life.

Heliod, Sun-Crowned

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature.
Whenever you gain life, put a +1/+1 counter on target creature or enchantment you control.
{1}{W}: Another target creature gains lifelink until end of turn.

Angelic Chorus

Whenever a creature enters the battlefield under your control, you gain life equal to its toughness.

Skyshooter

Reach (This creature can block creatures with flying.)
{T}, Sacrifice Skyshooter: Destroy target attacking or blocking creature with flying.

Mesa Unicorn

Conclave Mentor

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on that creature instead.
When Conclave Mentor dies, you gain life equal to its power.

Concordia Pegasus

Pheres-Band Warchief

Vigilance, trample
Other Centaur creatures you control get +1/+1 and have vigilance and trample.