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.

Iron Mastiff

Whenever Iron Mastiff attacks, roll a d20 for each player being attacked and ignore all but the highest roll.
1—9 | Iron Mastiff deals damage equal to its power to you.
10—19 | Iron Mastiff deals damage equal to its power to defending player.
20 | Iron Mastiff deals damage equal to its power to each opponent.

Thraben Purebloods

Rambunctious Mutt

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

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.)

Warclamp Mastiff

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

Supply Runners

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

Mischievous Pup

Flash
When Mischievous Pup enters the battlefield, return up to one other target permanent you control to its owner's hand.

Gore Vassal

Sacrifice Gore Vassal: Put a -1/-1 counter on target creature. Then if that creature's toughness is 1 or greater, regenerate it.

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.)

Isamaru, Hound of Konda

Akroan Mastiff

Alpine Watchdog

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

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.)

Release the Dogs

Create four 1/1 white Dog creature tokens.

Yoshimaru, Ever Faithful

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

Dogmeat, Ever Loyal

When Dogmeat enters the battlefield, 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.")

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.

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.

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.)

Gate Hound

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

Patrol Hound

Discard a card: Patrol Hound gains first strike until end of turn.

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.

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.

Spirited Companion

When Spirited Companion enters the battlefield, draw a card.

Encampment Keeper

First strike
{7}{W}, {T}, Sacrifice Encampment Keeper: Creatures you control get +2/+2 until end of turn.

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.)