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.

Regal Caracal

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

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Fleecemane Lion

{3}{G}{W}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
As long as Fleecemane Lion is monstrous, it has hexproof and indestructible.

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.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

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.

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.)

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

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.

Guardian Project

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

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Radiant Grove

({T}: Add {G} or {W}.)
Radiant Grove enters tapped.

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Skullclamp

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

Crib Swap

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

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Canopy Vista

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

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Qasali Slingers

Reach
Whenever Qasali Slingers or another Cat you control enters, you may destroy target artifact or enchantment.

Felidar Sovereign

Vigilance, lifelink
At the beginning of your upkeep, if you have 40 or more life, you win the game.

White Sun's Zenith

Create X 2/2 white Cat creature tokens. Shuffle White Sun's Zenith into its owner's library.

Cubwarden

Mutate {2}{W}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Lifelink
Whenever this creature mutates, create two 1/1 white Cat creature tokens with lifelink.

Runadi, Behemoth Caller

Whenever you cast a creature spell with mana value 5 or greater, that creature enters with X additional +1/+1 counters on it, where X is its mana value minus 4.
Creatures you control with three or more +1/+1 counters on them have haste.
{T}: Add {G}.

Vanquisher's Banner

As Vanquisher's Banner enters, 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.

Parallel Lives

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

Lion Sash

{W}: Exile target card from a graveyard. If it was a permanent card, put a +1/+1 counter on Lion Sash.
Equipped creature gets +1/+1 for each +1/+1 counter on Lion Sash.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Camaraderie

You gain X life and draw X cards, where X is the number of creatures you control. Creatures you control get +1/+1 until end of turn.

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.

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.

Universal Automaton

Changeling (This card is every creature type.)

Battlemage's Bracers

Equipped creature has haste.
Whenever an ability of equipped creature is activated, if it isn't a mana ability, you may pay {1}. If you do, copy that ability. You may choose new targets for the copy.
Equip {2}

King of the Pride

Adorned Pouncer

Double strike
Eternalize {3}{W}{W} ({3}{W}{W}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Cat with no mana cost. Eternalize only as a sorcery.)

Command Tower

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

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Release the Dogs

Create four 1/1 white Dog creature tokens.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Keeper of Fables

Whenever one or more non-Human creatures you control deal combat damage to a player, draw a card.

Heroic Intervention

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

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Reliquary Tower

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

Bolt Hound

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever Bolt Hound attacks, other creatures you control get +1/+0 until end of turn.

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.

Tocasia's Welcome

Whenever one or more creatures you control with mana value 3 or less enter, draw a card. This ability triggers only once each turn.

Gavony Township

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

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

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.

Kodama's Reach

Ajani, the Greathearted

Creatures you control have vigilance.
+1: You gain 3 life.
−2: Put a +1/+1 counter on each creature you control and a loyalty counter on each other planeswalker you control.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Prowling Serpopard

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

Cinder Glade

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

Loyal Warhound

Vigilance
When Loyal Warhound enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Selfless Savior

Sacrifice Selfless Savior: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

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.

Titanic Ultimatum

Until end of turn, creatures you control get +5/+5 and gain first strike, trample, and lifelink.

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.)

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Folk Hero

Commander creatures you own have "Whenever you cast a spell that shares a creature type with this creature, draw a card. This ability triggers only once each turn."

Jetmir, Nexus of Revels

Creatures you control get +1/+0 and have vigilance as long as you control three or more creatures.
Creatures you control also get +1/+0 and have trample as long as you control six or more creatures.
Creatures you control also get +1/+0 and have double strike as long as you control nine or more creatures.

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Brimaz, King of Oreskos

Vigilance
Whenever Brimaz, King of Oreskos attacks, create a 1/1 white Cat Soldier creature token with vigilance that's attacking.
Whenever Brimaz blocks a creature, create a 1/1 white Cat Soldier creature token with vigilance that's blocking that creature.

Felidar Retreat

Landfall — Whenever a land you control enters, choose one —
• Create a 2/2 white Cat Beast creature token.
• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

Selesnya Signet

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Boros Signet

Whitemane Lion

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

Pack Leader

Other Dogs you control get +1/+1.
Whenever Pack Leader attacks, prevent all combat damage that would be dealt this turn to Dogs you control.

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Spirited Companion

When Spirited Companion enters, draw a card.

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on Taurean Mauler.

Leonin Warleader

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

Anointed Procession

Prava of the Steel Legion

During your turn, creature tokens you control get +1/+4.
{3}{W}: Create a 1/1 white Soldier creature token.
Partner (You can have two commanders if both have partner.)

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.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Arcane Signet

Overgrown Farmland

Overgrown Farmland enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

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.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Sol Ring

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.

Lifecrafter's Bestiary

At the beginning of your upkeep, scry 1.
Whenever you cast a creature spell, you may pay {G}. If you do, draw a card.

Gruul Signet

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.)

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Instruments of War

Flash
As Instruments of War enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Akroma's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Creatures you control gain flying, vigilance, and double strike until end of turn.
• Creatures you control gain lifelink, indestructible, and protection from each color until end of turn.

Jinnie Fay, Jetmir's Second

If you would create one or more tokens, you may instead create that many 2/2 green Cat creature tokens with haste or that many 3/1 green Dog creature tokens with vigilance.

Esika's Chariot

When Esika's Chariot enters, create two 2/2 green Cat creature tokens.
Whenever Esika's Chariot attacks, create a token that's a copy of target token you control.
Crew 4

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.