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 token: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Alpine Watchdog

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

Generous Stray

Greater Tanuki

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

Faithful Watchdog

Vigilance
This creature enters with three +1/+1 counters on it.

Helpful Hunter

Yoshimaru, Ever Faithful

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

Rambunctious Mutt

When this creature enters, destroy target artifact or enchantment an opponent controls.

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 deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.

Carnival Barker

{T}: You have thirty seconds to laud a creature you control to any people outside the game. Until end of turn, that creature gains trample and haste and gets +X/+0, where X is the number of those people who applauded. Activate only as a sorcery and only once.

Trusty Retriever

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

Forum Familiar

Disguise {1}{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 this creature is turned face up, return another target permanent you control to its owner's hand and put a +1/+1 counter on this creature.

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.

Generous Pup

Vigilance
Whenever one or more +1/+1 counters are put on this creature, put a +1/+1 counter on each other creature you control. This ability triggers only once each 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.

Selfless Savior

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

Spirited Companion

Garrison Cat

When this creature dies, create a 1/1 white Human Soldier creature token.

Charmed Stray

Lifelink
When this creature enters, put a +1/+1 counter on each other creature you control named Charmed Stray.

Pack Leader

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

Phelia, Exuberant Shepherd

Flash
Whenever Phelia attacks, exile up to one other target nonland permanent. At the beginning of the next end step, return that card to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on Phelia.

Prideful Parent

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature enters, create a 1/1 white Cat creature token.

Pridemalkin

When this creature 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.)

Chandra's Embercat

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

Tanuki Transplanter

Whenever this creature or equipped creature attacks, add an amount of {G} equal to its power. Until end of turn, you don't lose this mana as steps and phases end.
Reconfigure {3} ({3}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a 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.