msem-instigator

Whenever Highpeak Rider attacks, search your library for a land card and put it onto the battlefield, then shuffle. Sacrifice that land at the beginning of the next end step.

Flying
When Highspire Informant enters, scry 1.

Wanderlust — Whenever Highwild Survivalist attacks, add {R} or {G}. If you control four or more differently named lands, add {R}{G} instead. Until end of turn, you don't lose mana added this way as steps and phases end.

Reach
Art of war — At the beginning of your end step, if Hinode Ranger dealt damage to an opponent this turn, put a +1/+1 counter on it.

{2}{R}, {T}, Exert Hinterland Ritualist, Sacrifice another creature: Hinterland Ritualist deals damage equal to the sacrificed creature's power to any target. Activate only as a sorcery. (An exerted creature won't untap during your next untap step.)

Whenever a creature dies, exile it.
Hiroto Jaakuna has all activated abilities of creature cards exiled with Hiroto Jaakuna.

Civilized — As long as you control an artifact, a creature, and an enchantment, prevent all combat damage that would be dealt to Hirsute Champion.

If a permanent with spirited entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Reach
When Hoarding Arachnid dies, draw a card.

First mate—Each nonland card in your starting deck has the same name as exactly one other card in your starting deck. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Vigilance
Whenever you cast a spell with the same name as a card in your graveyard, draw a card.

Hollow Queen can't be blocked by tokens.
Whenever Hollow Queen deals combat damage to a player or planeswalker, you may remove a counter from a permanent you control. If you do, put a +1/+1 counter on target creature you control.

Defender, deathtouch
Homestead Watcher gets +2/+0 and can attack as though it didn't have defender as long as you control another creature with defender.

{T}: Add {C}.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

When Honored Retinue enters, choose a creature you control. You may search your library for a creature card with the same name as that creature, reveal it, put it into your hand, then shuffle.

{T}: Untap another target enchanted creature you control. You may attach target Aura attached to that creature to another creature you control. Activate only as a sorcery.

Other Angels and Nephilim you control get +1/+0.
{3}{W}: Until end of turn, Hooded Mystic becomes an Angel, gets +3/+3 and gains flying.

Vigilance
Menagerie — When Hoof Cliff Trihorn enters, if there are five or more creature types among creatures you control, you may search your library for a card named Hoof Cliff Trihorn, reveal it, put it into your hand, then shuffle.

Hopeful Healer gets +1/+1 and has lifelink as long as you are glorious. (You are glorious as long as you have a glory counter.)

Trample
Harmony — Put a +1/+1 counter on target Warrior you control. You gain 1 life.
Whenever one or more Warriors you control deal combat damage to a player, harmonize. (Trigger up to one harmony of a permanent you control.)

Flying
When Horned Spy enters, look at target player's hand.

Whenever this creature enters or attacks, each player discards a card. If one or more land cards were discarded this way, this creature gains deathtouch until end of turn.
At the beginning of each opponent's end step, if that player didn't cast a spell this turn, that player loses 2 life and you gain 2 life.

Whenever this creature enters or attacks, put two -1/-1 counters on up to one target creature with power less than this creature's power.
Whenever another creature dies, you gain 2 life. If you controlled that creature, draw a card.

Whenever this creature enters or attacks, you may put a creature card with mana value 2 or less from your hand onto the battlefield. If you do, draw a card. Sacrifice that creature at the beginning of the next end step.
If a creature would enter under your control during combat on your turn, that creature enters tapped and attacking.

Whenever you cast a noncreature spell, any number of target creatures you control get +1/+1 until end of turn.
Whenever a creature you control deals an amount of combat damage exactly equal to its mana value to a player or planeswalker, draw a card.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Lifelink