Have

Enduring Bondwarden

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
When this creature dies, put its counters on target creature you control.

Backup Agent

When Backup Agent enters, put a +1/+1 counter on target creature.

Getting

Basri's Acolyte

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Basri's Acolyte enters, put a +1/+1 counter on each of up to two other target creatures you control.

Codespell Cleric

Vigilance
When Codespell Cleric enters, if it was the second spell you cast this turn, put a +1/+1 counter on target creature.

Snarling Wolf

{1}{G}: Snarling Wolf gets +2/+2 until end of turn. Activate only once each turn.

Plains

Tuskguard Captain

Outlast {G} ({G}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has trample.

Gnarlid Colony

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
If this creature was kicked, it enters with two +1/+1 counters on it.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Jukai Preserver

When Jukai Preserver enters, put a +1/+1 counter on target creature you control.
Channel — {2}{G}, Discard Jukai Preserver: Put a +1/+1 counter on each of up to two target creatures you control.

Forest

Fyndhorn Elves

Ecologist's Terrarium

When Ecologist's Terrarium enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, {T}, Sacrifice Ecologist's Terrarium: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Lifecrafter's Gift

Put a +1/+1 counter on target creature, then put a +1/+1 counter on each creature you control with a +1/+1 counter on it.

Massive Might

Target creature gets +2/+2 and gains trample until end of turn.

Larger Than Life

Target creature gets +4/+4 and gains trample until end of turn.

Uncharted Haven

This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Light the Way

Choose one —
• Put a +1/+1 counter on target creature or Vehicle. Untap it.
• Return target permanent you control to its owner's hand.

Blossoming Sands

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

Seven-Tail Mentor

When Seven-Tail Mentor enters or dies, put a +1/+1 counter on target creature or Vehicle you control.