msem-instigator

Whenever Thrinax Sporemother or another nontoken creature you control dies, create a 1/1 green Saproling creature token.
Whenever a creature card is exiled from your graveyard, create a 1/1 green Saproling creature token.

{T}: Add one mana of any type that a land you control could produce.
Augmented — At the beginning of your end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, untap Thriving Budling and put three +1/+1 counters on it.

Augmented — When you cast this spell, if it's your turn and you've spent {W}{U}{B}{R}{G} to cast spells this turn, copy it twice. You may choose new targets for the copies.
Thunder Road deals 3 damage to any target. You gain 3 life.

Vigilance, menace, trample, haste
Whenever you cast a spell, you may have Thunderous Avarice consume. If you do, put a +1/+1 counter on it. (To consume, sacrifice another creature or exile a creature card from your graveyard.)
Whenever an opponent casts a spell, they may have Thunderous Avarice consume. If they don't, put a +1/+1 counter on it.

Take an extra turn after this one. Exile Time in a Bottle.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, draw three cards.

Whenever a creature you control enters, Timid Thunderhorn gets +X/+X until end of turn, where X is that creature's power.

First strike
If one or more creature tokens would be created under your control, for each of those tokens, you may create three 2/2 green Cat Warrior creature tokens instead.

You may put cards with mana value 2 or less that permanents you control explore into your hand as though they were lands. (You won't get the counter if you do.)
Whenever Torch of Those Underfoot attacks, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Whenever Tortle Veteran or another Turtle you control enters, that creature explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Enchant creature
Enchanted creature gets +3/+3 and has trample.

Towering Boughs enters tapped.
{T}: Add {R} or {G}.
{3}{R}{G}: Until end of turn, Towering Boughs becomes a 6/6 red and green Treefolk creature with with trample and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Whenever another nontoken creature you control enters, that creature gains haste until end of turn. Then Tremor Seer deals 1 damage to any target.

I — Create a 1/1 red Hound creature token.
II — Create a 4/4 green Rhino Warrior creature token with trample.
III — You may have two target creatures you control fight. If you do and exactly one survives, put four +1/+1 counters on that creature.

Erratic, erratic, erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order. Repeat this process twice.)

Copy target spell twice. You may choose new targets for the copies. (A copy of a permanent spell enters as a token.)

At the beginning of your end step, draw a card if a creature died this turn. Then Tumultipede deals 2 damage to each opponent if two or more creatures died this turn. Then create three 1/1 green Saproling creature tokens if three or more creatures died this turn.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Other creatures you control have base power and toughness equal to this creature's base power and toughness.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
{4}{R}{G}: Twinblade Paragon gains double strike until end of turn.

{1}, Sacrifice another creature: Crystallize. Activate only as a sorcery. (Put a +1/+1 counter on a creature you control or create a Treasure.)
{W}{U}{B}{R}{G}: Target creature gets +3/+3 and gains trample until end of turn. Activate only as a sorcery.

Flying
When Tyrant of Tributes enters, target opponent sacrifices X permanents, where X is half the number of permanents they control, rounded up. You gain X life.

Trample, haste
When Tyrants of Bundan enters, tap all lands target player controls. They don't untap during their controller's next untap step.

You may play cards exiled with Azamir planeswalkers.
[+1]: Target player exiles a card from their hand.
[–3]: Exile target nonland permanent unless its controller exiles two other permanents they control.
[–7]: Target opponent may have you take two extra turns after this one. If they don't, you control them during their next turn.

{T}: Add {C}.
{3}{B}: Until end of turn, Tzhai's Throne becomes a 2/2 creature. It's still a land. It gets +2/+2 if {R} was spent to activate this ability, gets +2/+2 if {G} was spent, and gets +2/+2 if {W} was spent.

Enchant creature
As long as it's your turn, enchanted creature has indestructible.
Whenever enchanted creature attacks, it deals damage equal to its toughness to any target.

Lifelink
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on United Guardian. It loses this ability and gains “Whenever United Guardian attacks, create two 1/1 blue Elemental creature tokens with flying that are tapped and attacking.”