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.

Forest

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.

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.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Prowling Serpopard

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

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

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.

Jedit Ojanen of Efrava

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
Whenever Jedit Ojanen of Efrava attacks or blocks, create a 2/2 green Cat Warrior creature token with forestwalk.

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.

Jazal Goldmane

First strike (This creature deals combat damage before creatures without first strike.)
{3}{W}{W}: Attacking creatures you control get +X/+X until end of turn, where X is the number of attacking creatures.

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.)

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Rampant Growth

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

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.

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.)

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.)

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Command Tower

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

Animal Sanctuary

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

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Sol Ring

Jungle Shrine

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

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.

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Cinder Glade

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

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

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.

Whitemane Lion

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

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Kodama's Reach

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.

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.

Skullclamp

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

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.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

King of the Pride

Reliquary Tower

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

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.)

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.

Taurean Mauler

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

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.

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.

Regal Caracal

Other Cats you control get +1/+1 and have lifelink. (Damage dealt by those creatures also causes you to gain that much life.)
When this creature enters, create two 1/1 white Cat creature tokens with lifelink.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Swords to Plowshares

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

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.

Qasali Slingers

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

Pridemalkin

When Pridemalkin enters, put a +1/+1 counter on target creature you control.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Gavony Township

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

Intangible Virtue

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

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.

Rockfall Vale

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

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.)

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

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.

Keeper of Fables

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

Spirited Companion

When Spirited Companion enters, draw a card.

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.

Prowling Felidar

Vigilance
Landfall — Whenever a land you control enters, put a +1/+1 counter on Prowling Felidar.

Second Harvest

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

Farseek

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

Mountain

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."

Felidar Sovereign

Vigilance (Attacking doesn't cause this creature to tap.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your upkeep, if you have 40 or more life, you win the game.

Arcane Signet

Universal Automaton

Changeling (This card is every creature type.)

Leonin Warleader

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

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.

Canopy Vista

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

Wrath of God

Destroy all creatures. They can't be regenerated.

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.

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.

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.)

Evolving Wilds

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