Angel's Herald

{2}{W}, {T}, Sacrifice a green creature, a white creature, and a blue creature: Search your library for a card named Empyrial Archangel, put it onto the battlefield, then shuffle.

Yeva, Nature's Herald

Flash (You may cast this spell any time you could cast an instant.)
You may cast green creature spells as though they had flash.

Garruk, Savage Herald

+1: Reveal the top card of your library. If it's a creature card, put it into your hand. Otherwise, put it on the bottom of your library.
−2: Target creature you control deals damage equal to its power to another target creature.
−7: Until end of turn, creatures you control gain "You may have this creature assign its combat damage as though it weren't blocked."

Nyx Herald

At the beginning of combat on your turn, target enchanted creature or enchantment creature you control gets +1/+1 and gains trample until end of turn.

Herald of the Dreadhorde

When Herald of the Dreadhorde dies, amass Zombies 2. (Put two +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Herald of Dromoka

Vigilance
Other Warrior creatures you control have vigilance.

Herald of Leshrac

Flying
Cumulative upkeep—Gain control of a land you don't control. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Herald of Leshrac gets +1/+1 for each land you control but don't own.
When Herald of Leshrac leaves the battlefield, each player gains control of each land they own that you control.

Herald of the Sun

Flying
{3}{W}: Put a +1/+1 counter on another target creature with flying.

Herald of Anguish

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Flying
At the beginning of your end step, each opponent discards a card.
{1}{B}, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.

Demon's Herald

{2}{B}, {T}, Sacrifice a blue creature, a black creature, and a red creature: Search your library for a card named Prince of Thralls, put it onto the battlefield, then shuffle.

Niv-Mizzet Reborn

Flying
When Niv-Mizzet Reborn enters, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Gaea's Herald

Herald of Kozilek

Devoid (This card has no color.)
Colorless spells you cast cost {1} less to cast.

Herald of Secret Streams

Creatures you control with +1/+1 counters on them can't be blocked.

Herald of Torment

Bestow {3}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
At the beginning of your upkeep, you lose 1 life.
Enchanted creature gets +3/+3 and has flying.

River Heralds' Boon

Put a +1/+1 counter on target creature and a +1/+1 counter on up to one target Merfolk.

Harald, King of Skemfar

Menace (This creature can't be blocked except by two or more creatures.)
When Harald, King of Skemfar enters, look at the top five cards of your library. You may reveal an Elf, Warrior, or Tyvar card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Herald of Faith

Flying
Whenever Herald of Faith attacks, you gain 2 life.

Wirewood Herald

When Wirewood Herald dies, you may search your library for an Elf card, reveal that card, put it into your hand, then shuffle.

Azorius Herald

Azorius Herald can't be blocked.
When Azorius Herald enters, you gain 4 life.
When Azorius Herald enters, sacrifice it unless {U} was spent to cast it.

King Harald's Revenge

Until end of turn, target creature gets +1/+1 for each creature you control and gains trample. It must be blocked this turn if able.

Herald of Anafenza

Outlast {2}{W} ({2}{W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Whenever you activate Herald of Anafenza's outlast ability, create a 1/1 white Warrior creature token.

Forerunner of the Heralds

When Forerunner of the Heralds enters, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.
Whenever another Merfolk you control enters, put a +1/+1 counter on Forerunner of the Heralds.

Victory's Herald

Flying
Whenever Victory's Herald attacks, attacking creatures gain flying and lifelink until end of turn.

Harald Unites the Elves

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Mill three cards. You may put an Elf or Tyvar card from your graveyard onto the battlefield.
II — Put a +1/+1 counter on each Elf you control.
III — Whenever an Elf you control attacks this turn, target creature an opponent controls gets -1/-1 until end of turn.

Storm Herald

Haste
When Storm Herald enters, return any number of Aura cards from your graveyard to the battlefield attached to creatures you control. Exile those Auras at the beginning of your next end step. If those Auras would leave the battlefield, exile them instead of putting them anywhere else.

Benalish Heralds

Centaur's Herald

{2}{G}, Sacrifice Centaur's Herald: Create a 3/3 green Centaur creature token.

Herald of the Pantheon

Enchantment spells you cast cost {1} less to cast.
Whenever you cast an enchantment spell, you gain 1 life.

Herald of War

Flying
Whenever Herald of War attacks, put a +1/+1 counter on it.
Angel spells and Human spells you cast cost {1} less to cast for each +1/+1 counter on Herald of War.

Herald of Serra

Flying, vigilance
Echo {2}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Sphinx's Herald

{2}{U}, {T}, Sacrifice a white creature, a blue creature, and a black creature: Search your library for a card named Sphinx Sovereign, put it onto the battlefield, then shuffle.

Herald of the Host

Flying, vigilance
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Heraldic Banner

As Heraldic Banner enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Herald of the Fair

When Herald of the Fair enters, target creature you control gets +1/+1 until end of turn.

Mist-Cloaked Herald

Dragon's Herald

{2}{R}, {T}, Sacrifice a black creature, a red creature, and a green creature: Search your library for a card named Hellkite Overlord, put it onto the battlefield, then shuffle.

Flamekin Herald

Commander spells you cast have cascade. (Whenever you cast a commander, exile cards from the top of your library until you exile a nonland card with lesser mana value. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Behemoth's Herald

{2}{G}, {T}, Sacrifice a red creature, a green creature, and a white creature: Search your library for a card named Godsire, put it onto the battlefield, then shuffle.

Nebelgast Herald

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever Nebelgast Herald or another Spirit you control enters, tap target creature an opponent controls.

Brass Herald

As Brass Herald enters, choose a creature type.
When Brass Herald enters, reveal the top four cards of your library. Put all creature cards of the chosen type revealed this way into your hand and the rest on the bottom of your library in any order.
Creatures of the chosen type get +1/+1.

Herald of the Forgotten

Flying
When Herald of the Forgotten enters, if you cast it, return any number of target permanent cards with cycling abilities from your graveyard to the battlefield.