msem-instigator

When Dunecrest Pariah enters, you may search your library for a basic land or Desert card, reveal it, put it into your hand, then shuffle.
{T}, Sacrifice Dunecrest Pariah: You may put a land card from your hand onto the battlefield tapped.

When Dutiful Camel enters, put a +1/+1 counter on target creature you control.

{T}: Add {G}.

{G}: Each player exiles a card from their graveyard. If an instant or sorcery card is exiled this way, put a +1/+1 counter on Earthfeeder Worm.
Remove X +1/+1 counters from Earthfeeder Worm and sacrifice it: Exile X target cards from graveyards.

Whenever a land you control enters, upgrade target creature. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Vigilance
• Trample

{1}{G}, Sacrifice Edgeland Savant: Draw a card. You may put a land card from your hand onto the battlefield tapped.

When Elven Guard becomes the target of a spell you control, you may pay {G}. If you do, transform it.

Whenever a Role is attached to a creature you control or you cast a spell that targets a creature you control, put a +1/+1 counter on Enthusiastic Admirer.

Whenever Eternal Scout attacks, untap each other creature you control.

At the beginning of combat on your turn, if you control a creature with power greater than Ever-Gnawing Rat's, put a +1/+1 counter on Ever-Gnawing Rat.

{T}: Create an X/X green Elemental creature token, where X is Evoker of the Ancient Form's power.

When Evolving Elemental enters, scry 3, then reveal the top card of your library. Put a number of +1/+1 counters on Evolving Elemental equal to that card's mana value.

When Far-Realm Guardian enters, create a green Aura enchantment token named Wild Bounty attached to target creature. The token has enchant creature and “Enchanted creature gets +1/+1 and has ward {2}.”

{G}, {T}: Add {C}{C}.

{1}{G}, {T}, Sacrifice another nontoken creature: Create two tokens that are copies of the sacrificed creature, except they're 0/1. Activate only as a sorcery.

Improve {G} ({G}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
When Frontier Trackers dies, create a 1/1 green Elf creature token.

When GenTech Assistants enters, create an X/X green Mutant creature token.

When Genome Mapper enters, create a Function token with “Create an X/X green Mutant creature token, where X is this spell's mana value.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Flash
Reach
Glimmerbark Treant enters with X +1/+1 counters on it.
When Glimmerbark Treant leaves the battlefield, you gain life equal to its power.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
{3}{G}: Gloomhollow Woodlurker must be blocked this turn if able.

When Golna, the First Shah enters, create Shir, a legendary 3/3 white Cat creature token with trample.
Monument {5}{G}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

When Greenheart Squirrel enters, look at the top four cards of your library. You may reveal a basic land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Guardian of the Wurm enters, create a 6/6 green Wurm creature token with trample.

Flash
When Guppyfin Duelist enters, create a green Aura enchantment token named Piranha's Prowess attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.” Untap that creature.

When Harbinger of Growth enters, create a 1/1 green Saproling creature token.
{1}{G}, Sacrifice Harbinger of Growth: Populate. (Create a token that's a copy of a creature token you control.)