Druid of the Cowl

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

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.

Wose Pathfinder

{T}: Add one mana of any color.
{6}{G}, {T}: Another target creature gets +3/+3 and gains trample until end of turn.

Halana, Kessig Ranger

Reach
Whenever another creature you control enters, you may pay {2}. When you do, that creature deals damage equal to its power to target creature.
Partner (You can have two commanders if both have partner.)

Slime Against Humanity

Create a 0/0 green Ooze creature token with trample. Put X +1/+1 counters on it, where X is two plus the total number of cards you own in exile and in your graveyard that are Oozes or are named Slime Against Humanity.
A deck can have any number of cards named Slime Against Humanity.

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Centaur Nurturer

When Centaur Nurturer enters, you gain 3 life.
{T}: Add one mana of any color.

Seasonal Ritual

Add one mana of any color. (Then exile this card. You may cast the creature later from exile.)

Rosethorn Acolyte

Rosethorn Acolyte // Seasonal Ritual

Plant Beans

You may play an additional land this turn. (Then exile this card. You may cast the creature later from exile.)

Beanstalk Wurm

Beanstalk Wurm // Plant Beans

Vine Trellis

Defender (This creature can't attack.)
{T}: Add {G}.

Woodland Mystic

Deathbloom Gardener

Deathtouch
{T}: Add one mana of any color.

Leafkin Druid

{T}: Add {G}. If you control four or more creatures, add {G}{G} instead.

Slurrk, All-Ingesting

Slurrk, All-Ingesting enters with five +1/+1 counters on it.
Whenever Slurrk or another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Leaf Gilder

Orochi Sustainer

Elvish Aberration

{T}: Add {G}{G}{G}.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Quirion Elves

As Quirion Elves enters, choose a color.
{T}: Add {G}.
{T}: Add one mana of the chosen color.

Forest

Fyndhorn Elves

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Ornithopter of Paradise

Jewel Thief

Vigilance, trample
When Jewel Thief enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Rift Sower

{T}: Add one mana of any color.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Llanowar Elves

Naga Vitalist

{T}: Add one mana of any type that a land you control could produce.

Alloy Myr

Rootrider Faun

{T}: Add {G}.
{1}, {T}: Add one mana of any color.

Dawnhart Rejuvenator

When Dawnhart Rejuvenator enters, you gain 3 life.
{T}: Add one mana of any color.

Copper Myr

Wall of Roots

Defender
Put a -0/-1 counter on Wall of Roots: Add {G}. Activate only once each turn.

Werebear

{T}: Add {G}.
Threshold — Werebear gets +3/+3 as long as seven or more cards are in your graveyard.