Karlov Watchdog

Vigilance
Permanents your opponents control can't be turned face up during your turn.
Whenever you attack with three or more creatures, creatures you control get +1/+1 until end of turn.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

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.

Showdown of the Skalds

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile the top four cards of your library. Until the end of your next turn, you may play those cards.
II, III — Whenever you cast a spell this turn, put a +1/+1 counter on target creature you control.

Animal Sanctuary

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

Keeper of Fables

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

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.

Thought Vessel

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

Blink Dog

Double strike
Teleport — {3}{W}: Blink Dog phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)

Crazed Firecat

When Crazed Firecat enters, flip a coin until you lose a flip. Put a +1/+1 counter on Crazed Firecat for each flip you won.

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Savannah

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Mossdog

Whenever Mossdog becomes the target of a spell or ability an opponent controls, put a +1/+1 counter on Mossdog.

Anointed Procession

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

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.

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.)

Scythecat Cub

Trample
Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature you control. If this is the second time this ability has resolved this turn, double the number of +1/+1 counters on that creature instead.

Dogmeat, Ever Loyal

When Dogmeat enters, mill five cards, then return an Aura or Equipment card from your graveyard to your hand.
Whenever a creature you control that's enchanted or equipped attacks, create a Junk token. (It's an artifact with "{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Spirited Companion

When Spirited Companion enters, draw a card.

Wary Watchdog

When Wary Watchdog enters or dies, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Regathan Firecat

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Greater Tanuki

Trample
Channel — {2}{G}, Discard Greater Tanuki: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Ajani, Nacatl Avenger

+2: Put a +1/+1 counter on each Cat you control.
0: Create a 2/1 white Cat Warrior creature token. When you do, if you control a red permanent other than Ajani, Nacatl Avenger, he deals damage equal to the number of creatures you control to any target.
−4: Each opponent chooses an artifact, a creature, an enchantment, and a planeswalker from among the nonland permanents they control, then sacrifices the rest.

Ajani, Nacatl Pariah

When Ajani, Nacatl Pariah enters, create a 2/1 white Cat Warrior creature token.
Whenever one or more other Cats you control die, you may exile Ajani, then return him to the battlefield transformed under his owner's control.

Ajani, Nacatl Pariah // Ajani, Nacatl Avenger

Zodiac Dog

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)

Mountain

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.

Sol Ring

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, Loyal Companion, that many plus one +1/+1 counters are put on it instead.

Highcliff Felidar

Vigilance
When Highcliff Felidar enters, for each opponent, choose a creature with the greatest power among creatures that player controls. Destroy those creatures.

Yoshimaru, Ever Faithful

Whenever another legendary permanent you control enters, put a +1/+1 counter on Yoshimaru, Ever Faithful.
Partner (You can have two commanders if both have partner.)

Mad Dog

At the beginning of your end step, if Mad Dog didn't attack or come under your control this turn, sacrifice it.

Arcane Signet

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

Wild Nacatl

Wild Nacatl gets +1/+1 as long as you control a Mountain.
Wild Nacatl gets +1/+1 as long as you control a Plains.

Chrome Cat

Dogpile

Dogpile deals damage to any target equal to the number of attacking creatures you control.

Command Tower

Parallel Lives

Forest

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.

Plateau

Graceful Cat

Whenever Graceful Cat attacks, it gets +1/+1 until end of turn.

Blistering Firecat

Trample, haste
At the beginning of the end step, sacrifice Blistering Firecat.
Morph {R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Faithful Watchdog

Vigilance
Faithful Watchdog enters with three +1/+1 counters on it.

Plains

Sacred Cat

Lifelink
Embalm {W} ({W}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Cat with no mana cost. Embalm only as a sorcery.)

Dog Walker

Vigilance
Disguise {R/W}{R/W} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When Dog Walker is turned face up, create two tapped 1/1 white Dog creature tokens.

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Taiga

Junk

{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.

Canyon Wildcat

Penumbra Bobcat

When Penumbra Bobcat dies, create a 2/1 black Cat creature token.

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.

Kutzil, Malamet Exemplar

Your opponents can't cast spells during your turn.
Whenever one or more creatures you control each with power greater than its base power deals combat damage to a player, draw a card.

Guard Dogs

{2}{W}, {T}: Choose a permanent you control. Prevent all combat damage target creature would deal this turn if it shares a color with that permanent.

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.

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.

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.

Jetmir's Garden

({T}: Add {R}, {G}, or {W}.)
Jetmir's Garden enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

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.

Release the Dogs

Create four 1/1 white Dog creature tokens.

Tamanoa

Whenever a noncreature source you control deals damage, you gain that much life.

Resolute Watchdog

Defender
{1}, Sacrifice Resolute Watchdog: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Territorial Scythecat

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Landfall — Whenever a land you control enters, put a +1/+1 counter on Territorial Scythecat.

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.

Chandra's Embercat

{T}: Add {R}. Spend this mana only to cast an Elemental spell or a Chandra planeswalker spell.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

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.

Sterling Hound

When Sterling Hound enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Savage Firecat

Trample
Savage Firecat enters with seven +1/+1 counters on it.
Whenever you tap a land for mana, remove a +1/+1 counter from Savage Firecat.

Crib Swap

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