msem-instigator

Trample
Other creatures you control with trample get +2/+2.
{4}{R}{G}: Put a trample counter on target creature.

Reach
Stonebark Incinerator gets +2/+0 and has trample as long as you control a Dwarf.
Stonebark Incinerator gets +0/+2 and has vigilance as long as you control a Elf.

Whenever another creature you control enters, put your choice of a +1/+1 counter, a trample counter, or a haste counter on it.

When Suburban Runebrawler enters, exile target instant or sorcery card with mana value 2 or less from your graveyard.
Landfall — Once each turn, when a land you control enters, you may cast a copy of the exiled card without paying its mana cost.

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.)
Whenever Sullivan's Heralds or another creature you control becomes renowned, add mana equal to the number of +1/+1 counters on it in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

Target creature gets +3/+1 and gains trample until end of turn.

This spell can't be countered.
{R/G}: Target spell can't be countered.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Create a tapped colorless Mountain Forest land token. (It has “{T}: Add {R} or {G}.”)

Discard a card: Tender Warden gets +2/+2 until end of turn. Activate only during your turn.

Look at the top eight cards of your library. You may reveal up to one Elf and up to one Dwarf card from among them. Put the revealed cards into your hand and the rest on the bottom of your library in a random order. Tenuous Alliance deals 2 damage to you.

Attacking creatures you control have trample.
Whenever a creature you control attacks, you may remove any number of +1/+1 counters from that creature. If you do, it gets +2/+2 until end of turn for each counter removed this way.

Vigilance, trample
When Threshold Guardian enters, return a creature you control to its owner's hand.

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.

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

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.

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.

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.

Whenever a land becomes tapped, its controller sacrifices it and creates a Treasure token.

Flying, haste
Venwyn, the Dragon's Fang can't block.
At the beginning of combat on your turn, you may pay {1}{R/G}. If you do, create a token that's a copy of target creature you control with mana value 3 or less, except it's not legendary and has haste. Exile that token at end of combat.

{T}: Add {C}.
{T}, Pay 1 life: Add {R} or {G}.

You may play Vibrant Sandbar from your graveyard as long as seven or more cards are in your graveyard.
Vibrant Sandbar enters tapped.
{T}: Add {R} or {G}.
Cycling {1}{R}{G} ({1}{R}{G}, Discard this card: Draw a card.)