Zodiac Dog

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

Zurgo's Vanguard

Mobilize 1 (Whenever this creature attacks, create a tapped and attacking 1/1 red Warrior creature token. Sacrifice it at the beginning of the next end step.)
This creature's power is equal to the number of creatures you control.

Watchdog

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

Underworld Rage-Hound

This creature 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.)
This creature escapes with a +1/+1 counter on it.

Sterling Hound

When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Two-Headed Cerberus

Double strike (This creature deals both first-strike and regular combat damage.)

Tesak, Judith's Hellhound

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
Other Dogs you control have unleash.
Creatures you control with counters on them have haste.
Whenever Tesak attacks, add {R} for each attacking creature.