Zodiac Dog

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

Thieving Otter

Whenever this creature deals damage to an opponent, draw a card.

Blood Hound

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

Scrapyard Mongrel

As long as you control an artifact, this creature gets +2/+0 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Lutri, the Spellchaser

Companion — Each nonland card in your starting deck has a different name. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Flash
When Lutri enters, if you cast it, copy target instant or sorcery spell you control. You may choose new targets for the copy.

Chandra's Magmutt

{T}: This creature deals 1 damage to target player or planeswalker.

Chandra's Embercat

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

Bolt Hound

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever this creature attacks, other creatures you control get +1/+0 until end of turn.

Pack Mastiff

{1}{R}: Each creature you control named Pack Mastiff gets +1/+0 until end of turn.

Phantom Whelp

When this creature attacks or blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Chakram Retriever

Partner with Chakram Slinger (When this creature enters, 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.

Eon Frolicker

Flying
When this creature enters, if you cast it, target opponent takes an extra turn after this one. Until your next turn, you and planeswalkers you control gain protection from that player. (You and planeswalkers you control can't be targeted, dealt damage, or enchanted by anything controlled by that player.)

Frost Lynx

When this creature enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Karplusan Hound

Whenever this creature attacks, if you control a Chandra planeswalker, this creature deals 2 damage to any target.