Herald's Horn

As Herald's Horn enters the battlefield, 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.

Pride Sovereign

Pride Sovereign gets +1/+1 for each other Cat you control.
{W}, {T}, Exert Pride Sovereign: Create two 1/1 white Cat creature tokens with lifelink. (An exerted creature won't untap during your next untap step.)

Fleetfoot Panther

Flash
When Fleetfoot Panther enters the battlefield, return a green or white creature you control to its owner's hand.

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Harmonize

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Bronzehide Lion

{G}{W}: Bronzehide Lion gains indestructible until end of turn.
When Bronzehide Lion dies, return it to the battlefield. It's an Aura enchantment with enchant creature you control and "{G}{W}: Enchanted creature gains indestructible until end of turn," and it loses all other abilities.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Feline Sovereign

Other Cats you control get +1/+1 and have protection from Dogs.
Whenever one or more Cats you control deal combat damage to a player, destroy up to one target artifact or enchantment that player controls.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Spire Garden

Spire Garden enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Leonin Arbiter

Players can't search libraries. Any player may pay {2} for that player to ignore this effect until end of turn.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Altar of Bone

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters the battlefield tapped unless you control two or more basic lands.

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Qasali Pridemage

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{1}, Sacrifice Qasali Pridemage: Destroy target artifact or enchantment.

Guardian Project

Whenever a nontoken creature enters the battlefield under your control, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Vanquisher's Banner

As Vanquisher's Banner enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Dockside Extortionist

When Dockside Extortionist enters the battlefield, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Aura Shards

Whenever a creature enters the battlefield under your control, you may destroy target artifact or enchantment.

Clifftop Retreat

Clifftop Retreat enters the battlefield tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Selesnya Sanctuary

Selesnya Sanctuary enters the battlefield tapped.
When Selesnya Sanctuary enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Prowling Serpopard

This spell can't be countered.
Creature spells you control can't be countered.

Jazal Goldmane

First strike
{3}{W}{W}: Attacking creatures you control get +X/+X until end of turn, where X is the number of attacking creatures.

Cloudstone Curio

Whenever a nonartifact permanent enters the battlefield under your control, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Forest

Naya Charm

Choose one —
• Naya Charm deals 3 damage to target creature.
• Return target card from a graveyard to its owner's hand.
• Tap all creatures target player controls.

Xenagos, the Reveler

+1: Add X mana in any combination of {R} and/or {G}, where X is the number of creatures you control.
0: Create a 2/2 red and green Satyr creature token with haste.
−6: Exile the top seven cards of your library. You may put any number of creature and/or land cards from among them onto the battlefield.

Gavony Township

{T}: Add {C}.
{2}{G}{W}, {T}: Put a +1/+1 counter on each creature you control.

Hungry Lynx

Cats you control have protection from Rats. (They can't be blocked, targeted, or dealt damage by Rats.)
At the beginning of your end step, target opponent creates a 1/1 black Rat creature token with deathtouch.
Whenever a Rat dies, put a +1/+1 counter on each Cat you control.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice Eldrazi Monument.

Mirror Strike

All combat damage that would be dealt to you this turn by target unblocked creature is dealt to its controller instead.

Talisman of Unity

{T}: Add {C}.
{T}: Add {G} or {W}. Talisman of Unity deals 1 damage to you.

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, Temur Sabertooth gains indestructible until end of turn.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Sol Ring

Rin and Seri, Inseparable

Whenever you cast a Dog spell, create a 1/1 green Cat creature token.
Whenever you cast a Cat spell, create a 1/1 white Dog creature token.
{R}{G}{W}, {T}: Rin and Seri, Inseparable deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension.
As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

Triumph of the Hordes

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Rootbound Crag

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

King of the Pride

Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Samut, Voice of Dissent

Flash
Double strike, vigilance, haste
Other creatures you control have haste.
{W}, {T}: Untap another target creature.

Whitemane Lion

Flash
When Whitemane Lion enters the battlefield, return a creature you control to its owner's hand.

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. Talisman of Impulse deals 1 damage to you.

Plains

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. Talisman of Conviction deals 1 damage to you.

Alms Collector

Flash
If an opponent would draw two or more cards, instead you and that player each draw a card.

Copperline Gorge

Copperline Gorge enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

Impact Tremors

Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.

Kaheera, the Orphanguard

Companion — Each creature card in your starting deck is a Cat, Elemental, Nightmare, Dinosaur, or Beast card. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Vigilance
Each other creature you control that's a Cat, Elemental, Nightmare, Dinosaur, or Beast gets +1/+1 and has vigilance.

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Arcane Signet

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Selesnya Signet

Wooded Bastion

{T}: Add {C}.
{G/W}, {T}: Add {G}{G}, {G}{W}, or {W}{W}.

Leonin Warleader

Whenever Leonin Warleader attacks, create two 1/1 white Cat creature tokens with lifelink that are tapped and attacking.

Mirri, Weatherlight Duelist

First strike
Whenever Mirri, Weatherlight Duelist attacks, each opponent can't block with more than one creature this combat.
As long as Mirri, Weatherlight Duelist is tapped, no more than one creature can attack you each combat.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Gruul Signet

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Savannah

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Mountain

Plateau

Boros Signet

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature enters the battlefield under your control, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Regal Caracal

Other Cats you control get +1/+1 and have lifelink.
When Regal Caracal enters the battlefield, create two 1/1 white Cat creature tokens with lifelink.

Marisi, Breaker of the Coil

Your opponents can't cast spells during combat.
Whenever a creature you control deals combat damage to a player, goad each creature that player controls. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Aluren

Any player may cast creature spells with mana value 3 or less without paying their mana costs and as though they had flash.