Radha, Heir to Keld

Whenever Radha attacks, you may add {R}{R}.
{T}: Add {G}.

Whisperer of the Wilds

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

Iron Myr

Tangled Vale

Tangled Florahedron

Tangled Florahedron // Tangled Vale

Elvish Spirit Guide

Exile this creature from your hand: Add {G}.

Leaf Gilder

Leafkin Druid

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

Golden Hind

Llanowar Elves

Copper Myr

Intrepid Stablemaster

Reach
{T}: Add {G}.
{T}: Add two mana of any one color. Spend this mana only to cast Mount or Vehicle spells.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Vine Trellis

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

Moonscarred Werewolf

Vigilance
{T}: Add {G}{G}.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform this creature.

Scorned Villager

{T}: Add {G}.
At the beginning of each upkeep, if no spells were cast last turn, transform this creature.

Scorned Villager // Moonscarred Werewolf

Orochi Merge-Keeper

{T}: Add {G}.
As long as this creature is modified, it has "{T}: Add {G}{G}." (Equipment, Auras you control, and counters are modifications.)

Elmar, Ulvenwald Informant

Haste
Whenever you cast your second spell each turn, untap target creature, then investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")
Friends forever (You can have two commanders if both have friends forever.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Sol Ring

Wirewood Elf

Zhur-Taa Druid

{T}: Add {G}.
Whenever you tap this creature for mana, it deals 1 damage to each opponent.

Gruul Signet

Orochi Sustainer

Rootrider Faun

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

Quirion Elves

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

Druid of the Cowl

Tunnel Tipster

At the beginning of your end step, if a face-down creature entered the battlefield under your control this turn, put a +1/+1 counter on this creature.
{T}: Add {G}.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on this creature: Untap this creature.

Elvish Mystic

Werebear

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

Simian Spirit Guide

Scaled Nurturer

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, you gain 2 life.

Ulvenwald Abomination

Ulvenwald Captive

Defender
{T}: Add {G}.
{5}{G}{G}: Transform this creature.

Ulvenwald Captive // Ulvenwald Abomination

Heart Warden

{T}: Add {G}.
{2}, Sacrifice this creature: Draw a card.

Elfhame Druid

{T}: Add {G}.
{T}: Add {G}{G}. Spend this mana only to cast kicked spells.

Llanowar Mentor

{G}, {T}, Discard a card: Create a 1/1 green Elf Druid creature token named Llanowar Elves. It has "{T}: Add {G}."