Release the Dogs

Create four 1/1 white Dog creature tokens.

Underworld Rage-Hound

Underworld Rage-Hound attacks each combat if able.
Escape—{3}{R}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Underworld Rage-Hound escapes with a +1/+1 counter on it.

Chakram Slinger

Partner with Chakram Retriever (When this creature enters the battlefield, target player may put Chakram Retriever into their hand from their library, then shuffle.)
{R}, {T}: Chakram Slinger deals 2 damage to target player or planeswalker.

Trusty Retriever

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

Mongrel Pack

When Mongrel Pack dies during combat, create four 1/1 green Dog creature tokens.

Ronin Houndmaster

Haste
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

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.

Blood Hound

Whenever you're dealt damage, you may put that many +1/+1 counters on Blood Hound.
At the beginning of your end step, remove all +1/+1 counters from Blood Hound.

Mordenkainen

+2: Draw two cards, then put a card from your hand on the bottom of your library.
−2: Create a blue Dog Illusion creature token with "This creature's power and toughness are each equal to twice the number of cards in your hand."
−10: Exchange your hand and library, then shuffle. You get an emblem with "You have no maximum hand size."

Haldan, Avid Arcanist

Partner with Pako, Arcane Retriever (When this creature enters the battlefield, target player may put Pako into their hand from their library, then shuffle.)
You may play lands and cast noncreature spells from among cards you exiled that have fetch counters on them, and you may spend mana as though it were mana of any color to cast those spells.

Supply Runners

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

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.

Fiery Hellhound

{R}: Fiery Hellhound gets +1/+0 until end of turn.

Abzan Beastmaster

At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness.

Rakdos Ragemutt

Watchdog

Watchdog blocks each combat if able.
As long as Watchdog is untapped, all creatures attacking you get -1/-0.

Ashmouth Hound

Whenever Ashmouth Hound blocks or becomes blocked by a creature, Ashmouth Hound deals 1 damage to that creature.

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Chakram Retriever

Partner with Chakram Slinger (When this creature enters the battlefield, target player may put Chakram Slinger into their hand from their library, then shuffle.)
Whenever you cast a spell during your turn, untap target creature.

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters the battlefield, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

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.

Wildfire Cerberus

{5}{R}{R}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
When Wildfire Cerberus becomes monstrous, it deals 2 damage to each opponent and each creature they control.

Banehound

Ainok Guide

When Ainok Guide enters the battlefield, choose one —
• Put a +1/+1 counter on Ainok Guide.
• Search your library for a basic land card, reveal it, then shuffle and put that card on top.

Jiang Yanggu

+1: Target creature gets +2/+2 until end of turn.
−1: If you don't control a creature named Mowu, create Mowu, a legendary 3/3 green Dog creature token.
−5: Until end of turn, target creature gains trample and gets +X/+X, where X is the number of lands you control.

Mortis Dogs

Whenever Mortis Dogs attacks, it gets +2/+0 until end of turn.
When Mortis Dogs dies, target player loses life equal to its power.

Floodhound

{3}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Pyre Hound

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Pyre Hound.

Ooze Flux

{1}{G}, Remove one or more +1/+1 counters from among creatures you control: Create an X/X green Ooze creature token, where X is the number of +1/+1 counters removed this way.

Longshot Squad

Outlast {1}{G} ({1}{G}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has reach. (A creature with reach can block creatures with flying.)

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.)

Alpine Watchdog

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

Hound of Griselbrand

Double strike
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

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.)

Ainok Bond-Kin

Outlast {1}{W} ({1}{W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has first strike.

Gate Hound

Creatures you control have vigilance as long as Gate Hound is enchanted.

Isamaru, Hound of Konda

Mossdog

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

Affa Guard Hound

Flash (You may cast this spell any time you could cast an instant.)
When Affa Guard Hound enters the battlefield, target creature gets +0/+3 until end of turn.

Elven Warhounds

Whenever Elven Warhounds becomes blocked by a creature, put that creature on top of its owner's library.

Power Conduit

{T}, Remove a counter from a permanent you control: Choose one —
• Put a charge counter on target artifact.
• Put a +1/+1 counter on target creature.

Rambunctious Mutt

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

Loyal Warhound

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

Dreadhound

When Dreadhound enters the battlefield, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Roar of the Crowd

Choose a creature type. Roar of the Crowd deals damage to any target equal to the number of permanents you control of the chosen type.

Underworld Cerberus

Underworld Cerberus can't be blocked except by three or more creatures.
Cards in graveyards can't be the targets of spells or abilities.
When Underworld Cerberus dies, exile it and each player returns all creature cards from their graveyard to their hand.

Reflections of Littjara

As Reflections of Littjara enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Akoum Hellhound

Landfall — Whenever a land enters the battlefield under your control, Akoum Hellhound gets +2/+2 until end of turn.

Kunoros, Hound of Athreos

Vigilance, menace, lifelink
Creature cards in graveyards can't enter the battlefield.
Players can't cast spells from graveyards.

Plague Dogs

When Plague Dogs dies, all creatures get -1/-1 until end of turn.
{2}, Sacrifice Plague Dogs: Draw a card.

Alpine Houndmaster

When Alpine Houndmaster enters the battlefield, you may search your library for a card named Alpine Watchdog and/or a card named Igneous Cur, reveal them, put them into your hand, then shuffle.
Whenever Alpine Houndmaster attacks, it gets +X/+0 until end of turn, where X is the number of other attacking creatures.

Fate Transfer

Move all counters from target creature onto another target creature.

Dogpile

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

Thrashing Mossdog

Reach (This creature can block creatures with flying.)
Scavenge {4}{G}{G} ({4}{G}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Pako, Arcane Retriever

Partner with Haldan, Avid Arcanist
Haste
Whenever Pako, Arcane Retriever attacks, exile the top card of each player's library and put a fetch counter on each of them. Put a +1/+1 counter on Pako for each noncreature card exiled this way.

Igneous Cur

{1}{R}: Igneous Cur gets +2/+0 until end of turn.

Ghost Hounds

Vigilance
Whenever Ghost Hounds blocks or becomes blocked by a white creature, Ghost Hounds gains first strike until end of turn.

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.

Bioshift

Move any number of +1/+1 counters from target creature onto another target creature with the same controller.

Ainok Survivalist

Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Ainok Survivalist is turned face up, destroy target artifact or enchantment an opponent controls.