Horse

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Arctic Treeline

({T}: Add {G} or {W}.)
Arctic Treeline enters tapped.

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Beast

Archangel of Thune

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever you gain life, put a +1/+1 counter on each creature you control.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Plains

Forest

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.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Insect

Evolution Witness

{1}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Whenever one or more +1/+1 counters are put on Evolution Witness, return target permanent card from your graveyard to your hand.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of Scute Swarm instead.

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Lush Portico

({T}: Add {G} or {W}.)
Lush Portico enters tapped.
When Lush Portico enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Blossoming Sands

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {W}.

Requisition Raid

Spree (Choose one or more additional costs.)
+ {1} — Destroy target artifact.
+ {1} — Destroy target enchantment.
+ {1} — Put a +1/+1 counter on each creature target player controls.

Birds of Paradise

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Luminarch Aspirant

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.

Lapse of Certainty

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Herd Baloth

Whenever one or more +1/+1 counters are put on Herd Baloth, you may create a 4/4 green Beast creature token.

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.