Domri's Ambush

Put a +1/+1 counter on target creature you control. Then that creature deals damage equal to its power to target creature or planeswalker you don't control.

Goblin Razerunners

{1}{R}, Sacrifice a land: Put a +1/+1 counter on this creature.
At the beginning of your end step, you may have this creature deal damage equal to the number of +1/+1 counters on it to target player or planeswalker.

Gruul War Chant

Attacking creatures you control get +1/+0 and have menace.

Krenko, Tin Street Kingpin

Whenever Krenko attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Trollbred Guardian

{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Reap the Past

Return X cards at random from your graveyard to your hand. Exile Reap the Past.

Wildborn Preserver

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)
Whenever another non-Human creature you control enters, you may pay {X}. When you do, put X +1/+1 counters on this creature.

Ravenous Slime

This creature can't be blocked by creatures with power 2 or less.
If a creature an opponent controls would die, instead exile it and put a number of +1/+1 counters equal to that creature's power on this creature.

Aerie Ouphes

Sacrifice this creature: It deals damage equal to its power to target creature with flying.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Armorcraft Judge

When this creature enters, draw a card for each creature you control with a +1/+1 counter on it.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Crowned Ceratok

Trample
Each creature you control with a +1/+1 counter on it has trample.

Durable Handicraft

Whenever a creature you control enters, you may pay {1}. If you do, put a +1/+1 counter on that creature.
{5}{G}, Sacrifice this enchantment: Put a +1/+1 counter on each creature you control.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Trapjaw Kelpie

Flash
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, that many plus one +1/+1 counters are put on it instead.

Grumgully, the Generous

Each other non-Human creature you control enters with an additional +1/+1 counter on it.

Pollenbright Druid

When this creature enters, choose one —
• Put a +1/+1 counter on target creature.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Bloodbraid Elf

Haste (This creature can attack and {T} as soon as it comes under your control.)
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Grazing Kelpie

{G/U}, Sacrifice this creature: Put target card from a graveyard on the bottom of its owner's library.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Planewide Celebration

Choose four. You may choose the same mode more than once.
• Create a 2/2 Citizen creature token that's all colors.
• Return target permanent card from your graveyard to your hand.
• Proliferate.
• You gain 4 life.

Ferocity of the Wilds

Attacking non-Human creatures you control get +1/+0 and have trample.

Safehold Elite

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Bloom Hulk

When this creature enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Arlinn, Voice of the Pack

Each creature you control that's a Wolf or a Werewolf enters with an additional +1/+1 counter on it.
−2: Create a 2/2 green Wolf creature token.

Rubblebelt Raiders

Whenever this creature attacks, put a +1/+1 counter on it for each attacking creature you control.

Cytoplast Root-Kin

Graft 4 (This creature enters with four +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
When this creature enters, put a +1/+1 counter on each other creature you control with a +1/+1 counter on it.
{2}: Move a +1/+1 counter from target creature you control onto this creature.