Forest

Master Chef

Commander creatures you own have "This creature enters with an additional +1/+1 counter on it" and "Other creatures you control enter with an additional +1/+1 counter on them."

Crowned Ceratok

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

Fyndhorn Elves

Fairgrounds Trumpeter

At the beginning of each end step, if a +1/+1 counter was put on a permanent under your control this turn, put a +1/+1 counter on this creature.

Scale the Heights

Put a +1/+1 counter on up to one target creature. You gain 2 life. You may play an additional land this turn.
Draw a card.

Elvish Mystic

Mutant's Prey

Target creature you control with a +1/+1 counter on it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Fertilid

This creature enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from this creature: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Servant of the Scale

This creature enters with a +1/+1 counter on it.
When this creature dies, put X +1/+1 counters on target creature you control, where X is the number of +1/+1 counters on this creature.

Duskshell Crawler

When this creature enters, put a +1/+1 counter on target creature.
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.)

Loyal Guardian

Trample
Lieutenant — At the beginning of combat on your turn, if you control your commander, put a +1/+1 counter on each creature you control.

Titanic Brawl

This spell costs {1} less to cast if it targets a creature you control with a +1/+1 counter on it.
Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

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.)

Aquastrand Spider

Graft 2 (This creature enters with two +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{G}: Target creature with a +1/+1 counter on it gains reach until end of turn. (It can block creatures with flying.)

Longshot Squad

Outlast {1}{G} ({1}{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 reach. (A creature with reach can block creatures with flying.)

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

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.

Gaea's Gift

Put a +1/+1 counter on target creature you control. It gains reach, trample, hexproof, and indestructible until end of turn. (It can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Pridemalkin

When this creature enters, put a +1/+1 counter on target creature you control.
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.)

Ashnod's Transmogrant

{T}, Sacrifice this artifact: Put a +1/+1 counter on target nonartifact creature. That creature becomes an artifact in addition to its other types.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

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.

Ancient Animus

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)