Mushroom Watchdogs

Sacrifice a Food: Put a +1/+1 counter on Mushroom Watchdogs. It gains vigilance until end of turn. Activate only as a sorcery.

Sophia, Dogged Detective

When Sophia, Dogged Detective enters the battlefield, create Tiny, a legendary 2/2 green Dog Detective creature token with trample.
{1}, Sacrifice an artifact token: Put a +1/+1 counter on each Dog you control.
Whenever a Dog you control deals combat damage to a player, create a Food token, then investigate.

Impostor of the Sixth Pride

Changeling (This card is every creature type.)

Woodland Changeling

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.

Colossification

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

Akroan Mastiff

Aggressive Instinct

Target creature you control deals damage equal to its power to target creature you don't control.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Kodama's Reach

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.

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Alpine Watchdog

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

Talisman of Unity

{T}: Add {C}.
{T}: Add {G} or {W}. Talisman of Unity deals 1 damage to you.

Morska, Undersea Sleuth

You have no maximum hand size.
At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you draw your second card each turn, put two +1/+1 counters on Morska, Undersea Sleuth.

Jazal Goldmane

First strike
{3}{W}{W}: Attacking creatures you control get +X/+X until end of turn, where X is the number of attacking creatures.

Spirited Companion

When Spirited Companion enters the battlefield, draw a card.

Webweaver Changeling

Changeling (This card is every creature type.)
Reach
When Webweaver Changeling enters the battlefield, if there are three or more creature cards in your graveyard, you gain 5 life.

Universal Automaton

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.

Pledge of Unity

Put a +1/+1 counter on each creature you control. You gain 1 life for each creature you control.

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.

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.

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.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Explore

You may play an additional land this turn.
Draw a card.

Warclamp Mastiff

First strike (This creature deals combat damage before creatures without first strike.)

Chameleon Colossus

Changeling (This card is every creature type.)
Protection from black
{2}{G}{G}: Chameleon Colossus gets +X/+X until end of turn, where X is its power.

Prava of the Steel Legion

As long as it's 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.)

Bayou Groff

As an additional cost to cast this spell, sacrifice a creature or pay {3}.

Bloodline Pretender

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

Harmonize

Release the Dogs

Create four 1/1 white Dog creature tokens.

Emmara Tandris

Prevent all damage that would be dealt to creature tokens you control.

Supply Runners

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

Sol Ring

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.

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Wild Dogs

At the beginning of your upkeep, if a player has more life than each other player, the player with the most life gains control of Wild Dogs.
Cycling {2} ({2}, Discard this card: Draw a card.)

K-9, Mark I

Negative — As long as K-9, Mark I is untapped, other legendary creatures you control have ward {1}.
Affirmative — {1}{U}, {T}: Target legendary creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Isamaru, Hound of Konda

Guardian Gladewalker

Changeling (This card is every creature type.)
When Guardian Gladewalker enters the battlefield, put a +1/+1 counter on target creature.

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."

Irregular Cohort

Changeling (This card is every creature type.)
When Irregular Cohort enters the battlefield, create a 2/2 colorless Shapeshifter creature token with changeling.

Boros Mastiff

Battalion — Whenever Boros Mastiff and at least two other creatures attack, Boros Mastiff gains lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Cathar's Companion

Whenever you cast a noncreature spell, Cathar's Companion gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

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.

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.

Keeper of Fables

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

Arcane Signet

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

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.)

Avian Changeling

Changeling (This card is every creature type.)
Flying

Floodhound

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

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.)

Overrun

Creatures you control get +3/+3 and gain trample until end of turn.

Aggressive Mammoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other creatures you control have trample.

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.

Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw, Terror of Qal Sisma attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Cultivate

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.

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters the battlefield, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Pridemalkin

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

Rampaging Growth

Search your library for a basic land card, put it on the battlefield, then shuffle. Until end of turn, that land becomes a 4/3 Insect creature with reach and haste. It's still a land.

Rambunctious Mutt

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