msem-instigator

When Greedy Insects enters, exile up to one target artifact or enchantment until Greedy Insects leaves the battlefield.

Whenever Green Pelt Hart or another Elk creature you control deals combat damage to a player, draw that many cards.

Menace
Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)

Flying, haste
Whenever Grieving Revenant attacks, it deals 1 damage to each other creature you control.

Sacrifice another creature: Grisly Rougarou deals damage equal to the sacrificed creature's power to any target.

Grizzled Den enters tapped.
{T}: Add {R} or {G}.
{3}{R}{G}: Until end of turn, Grizzled Den becomes a Bear creature with trample in addition to its other types.
Scavenge {4}{R}{G}

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Sacrifice another creature: Grotesque Defiler gains flying until end of turn.
Whenever Grotesque Defiler deals combat damage to a player, if you're in a renaissance, that player discards a card.

When Grotto Scarab enters, create two 1/1 green Insect creature tokens for each creature you controlled that died this turn.

Other creatures you control that are Knights or have Adventures get +1/+1.

Hexproof, trample
Whenever Gui, the Islandbringer deals combat damage to an opponent, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.

Menace
Death knell — Put a +1/+1 counter on Guiltless Wraith. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

When Gulch Custodian enters, return an artifact you control to its owner's hand.

Flying
Ward—Pay 4 life.
Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, return HO-20 Rising Sun from your graveyard to the battlefield tapped.

Flying
If a source you control would deal noncombat damage to a permanent or player, you may have it deal damage equal to Hadak's power instead.

Flying
When Hallowed Executioner enters, it deals 2 damage to each creature without flying.

Hexproof
Deploy 4 (As this enters, you may tap any number of other creatures you control with total power 4 or more.)
When Hamlet Witch enters deployed, return target card from your graveyard to your hand.

Indestructible
Whenever Hannaru the Conqueror attacks, put a +1/+1 counter on each creature you control.

Flying, trample
Whenever Hao'Tai, the Ancient One deals combat damage to a player, exile the top four cards of that player's library. Until end of turn, you may cast instant, sorcery, and creature cards from among those exiled cards, and you may spend mana as though it were mana of any color to cast them.

Trample
Other Dwarves and Elves you control get +1/+1.
If Harl and Finn or another Dwarf or Elf you control entering the battlefield or attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Whenever Harvester of Secrets or another creature enters from your graveyard, you may draw a card.
Unearth {2}{U}{B} ({2}{U}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

Whenever you cast an instant or sorcery spell from your hand, put that card onto the battlefield face down as a 2/2 creature instead of putting it into your graveyard as it resolves.
Whenever a face-down creature you control deals combat damage to an opponent, you may exile it. If you do, you may cast it without paying its mana cost.

When Haughty Paladin enters, you may sacrifice another artifact or creature. If you do, tap all creatures your opponents control.

At the beginning of each player's upkeep, sacrifice Hayuan, the Misjudged if that player controls a creature with power 2 or less.
When Hayuan dies, create X Idol tokens, where X is the number of creatures you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flying, vigilance, deathtouch, lifelink

Whenever a creature in Heaven's Fire Ascetic's pack attacks, that creature deals 1 damage to defending player. (Two or more creatures you control with equal power are in a pack.)