This deck is absolutely incredible and took me to top 300 legend this season. My wr was something like 70% while climbing from 5 to 1, then tapered off as I started getting to the high ranks. I don't track stats because I don't have hsreplay premium but I hit legend in 50 games or less.
Matchups & Mulligan Guide
Rouge: Slightly Unfavored to Unfavored. In general, your goal in this matchup is to survive their aggression - your lategame is a lot more powerful than theirs is, you just have to get there. Getting down an early Rat Trap is massive in this matchup, as if you can slow down his first 5 turns you'll be in a very good position. Stay out of rog's burst with dire frenzy'd scalehides, get to the lategame then finish them off once they're out of gas.
Warrior: Heavily Favored. In this matchup you want to Dire Frenzy back a couple of Timber Wolf, tutor them back with Master's Call and combo them with Tundra Rhino for a massive amount of damage. Casting Dire Frenzy on another charger like Tundra Rhino or Huffer is also fine. Against Bomb Warrior you're less heavily favored but still favored - consider shuffling back some Vicious Scalehides with Dire Frenzy to outheal their bomb damage.
Druid: Even. Keep Unleash the Hounds. This is a matchup where your win depends on you drawing Scavenging Hyena, Timber Wolf, Springpaw and/or Unleash the Hounds. If you can pull off a massive Unleash the Hounds + Scavenging Hyena turn, you will win - druids no longer has any way to deal with massive minions (RIP Naturalize). If you don't draw that combo though it'll be tough. If you're somehow playing against a Heal Druid then idk what to tell you, I didn't play vs any of those. Guess you just aggro them down like Mage and Priest.
Shaman: Even to Slightly Favored vs Murloc Shaman, Favored vs Morpher Shaman/Control Shaman. Murloc Shaman, like Token Druid, is a matchup where Unleash the Hounds and Scavenging Hyena are really good. You're also able to win this one by just outlasting their threats though. Keep their boards as clear as possible because that deck lives and dies off the board. Against Morpher Shaman aggro them down and clear their threats using your removal package. You want to play vs Control Shaman in much of the same way you play vs Control Warrior - Dire Frenzy Timber Wolf or chargers back in your deck and smack them in the face for a lot in the lategame.
Hunter: Slightly Favored to Favored. Against Bomb Hunter you're looking to Dire Frenzy back a couple of Vicious Scalehide; if you can outheal their Goblin Bomb damage you're set. Against Secret Hunter you want to remove their very limited amount of threats and use your superior draw engine to blast through your deck while your opponent gasses out. Try not to activate Rat Trap before you can deal with it though. The matchup against Midrange Hunter often comes down to whoever has the larger Zul'jin. Since your Zul'jin gives you a green christmas tree and theirs doesn't, you'll probably win.
Mage: Favored. just aggro them down lol. Against Miracle Mage, Rat Trap is ridiculously good - pretty much guaranteed to trigger sooner or later. Against Conjuring Mage deadly shots are obviously very good. Removing their giants the turn they come down is pretty important, otherwise smack their face because they don't have much healing. Both these decks have lots of trouble dealing with hyenas, zul'jin, wide boards, and hunter hero power.
Priest: Favored. Rat Trap is super good vs Nomi Priest since they play a lot of spells very fast. Snipe is also really good vs them since they run like 7 minions total, even though I'd probably still toss it in the mull. Try to aggro them down like you do mage, or at least put enough pressure on them so that they're forced to Seance Grave Horror instead of Chef Nomi. You can deal with a single wave of greasefire elementals with Zul'jin; it's waves 2 and 3 that really get you.
Warlock: Slightly Favored. Like the Murloc Shaman and Token Druid matchups, Unleash the Hounds and Scavenging Hyena win you the game. Unlike Murloc Shaman and Token Druid, Zoolock can gas out a lot faster, and their hero takes a lot of damage too due to Life Tap. It's a lot easier to stabilize vs them, and always be on the lookout for a surprise lethal.
Paladin: Unfavored. Their mechs go really tall, have taunt, and come online far faster than your lategame Dire Frenzy package does. Your only hope is to aggro them down while clearing all their mechs and set them low enough so that your hero power can finish them off before they start sending massive mechs to your face while praying they don't draw Zilliax.
Let me know if you want a deck choice explanation or have other questions.