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.

Mountain

Obelisk of Urd

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.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Forest

Wind-Scarred Crag

Wind-Scarred Crag enters tapped.
When Wind-Scarred Crag enters, you gain 1 life.
{T}: Add {R} or {W}.

Cabaretti Ascendancy

At the beginning of your upkeep, look at the top card of your library. If it's a creature or planeswalker card, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it on the bottom of your library.

White Sun's Zenith

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

Getaway Car

Haste
Whenever Getaway Car attacks or blocks, return up to one target creature that crewed it this turn to its owner's hand.
Crew 1

Goldhound

First strike
Menace (This creature can't be blocked except by two or more creatures.)
{T}, Sacrifice Goldhound: Add one mana of any color.

King of the Pride

Toski, Bearer of Secrets

This spell can't be countered.
Indestructible
Toski, Bearer of Secrets attacks each combat if able.
Whenever a creature you control deals combat damage to a player, draw a card.

Make a Stand

Creatures you control get +1/+0 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

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.

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.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Plains

Rugged Highlands

Rugged Highlands enters tapped.
When Rugged Highlands enters, you gain 1 life.
{T}: Add {R} or {G}.

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.

Whitemane Lion

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

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

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.)

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.

Keeper of Fables

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

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.

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.

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.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters with an additional +1/+1 counter on it.

Rite of Harmony

Whenever a creature or enchantment you control enters this turn, draw a card.
Flashback {2}{G}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Cathars' Crusade

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

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.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Stoneforge Masterwork

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it.
Equip {2}

Impostor of the Sixth Pride

Changeling (This card is every creature type.)

Jewel Thief

Vigilance, trample
When Jewel Thief enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Cabaretti Courtyard

When Cabaretti Courtyard enters, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Evolving Wilds

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

Felidar Cub

Sacrifice Felidar Cub: Destroy target enchantment.

Feral Prowler

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.

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.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

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.

Gilded Lotus

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.

Command Tower

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

Sol Ring

Shalai, Voice of Plenty

Flying
You, planeswalkers you control, and other creatures you control have hexproof.
{4}{G}{G}: Put a +1/+1 counter on each creature you control.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Trusty Retriever

When Trusty Retriever enters, choose one —
• Put a +1/+1 counter on Trusty Retriever.
• Return target artifact or enchantment card from your graveyard to your hand.

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.)

Secret Rendezvous

You and target opponent each draw three cards.

Commander's Sphere

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

Generous Stray

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

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.)

Intangible Virtue

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

Sacred Foundry

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

Healer of the Pride

Whenever another creature you control enters, you gain 2 life.

Release the Dogs

Create four 1/1 white Dog creature tokens.

Huatli, Radiant Champion

+1: Put a loyalty counter on Huatli, Radiant Champion for each creature you control.
−1: Target creature gets +X/+X until end of turn, where X is the number of creatures you control.
−8: You get an emblem with "Whenever a creature you control enters, you may draw a card."

Arcane Signet

Rocco, Cabaretti Caterer

When Rocco, Cabaretti Caterer enters, if you cast it, you may search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Racers' Ring

Racers' Ring enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}, {T}, Sacrifice Racers' Ring: Draw a card.

Ormendahl, Profane Prince

Westvale Abbey

{T}: Add {C}.
{5}, {T}, Pay 1 life: Create a 1/1 white and black Human Cleric creature token.
{5}, {T}, Sacrifice five creatures: Transform Westvale Abbey, then untap it.

Westvale Abbey // Ormendahl, Profane Prince

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.

Rampant Growth

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

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.)

Spirited Companion

When Spirited Companion enters, draw a card.

Felidar Sovereign

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

Selesnya Locket

{T}: Add {G} or {W}.
{G/W}{G/W}{G/W}{G/W}, {T}, Sacrifice Selesnya Locket: Draw two cards.

Darksteel Mutation

Enchant creature
Enchanted creature is an Insect artifact creature with base power and toughness 0/1 and has indestructible, and it loses all other abilities, card types, and creature types.

Rambunctious Mutt

When Rambunctious Mutt enters, destroy target artifact or enchantment an opponent controls.

Supply Runners

When Supply Runners enters, put a +1/+1 counter on each other creature you control.

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.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate.

Blossoming Sands

Blossoming Sands enters tapped.
When Blossoming Sands enters, you gain 1 life.
{T}: Add {G} or {W}.

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.

Skyhunter Strike Force

Flying
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Lieutenant — As long as you control your commander, other creatures you control have melee.

Phabine, Boss's Confidant

Creature tokens you control have haste.
Parley — At the beginning of combat on your turn, each player reveals the top card of their library. For each land card revealed this way, you create a 1/1 green and white Citizen creature token. Then creatures you control get +1/+1 until end of turn for each nonland card revealed this way. Then each player draws a card.