Hearthpwn

Yep . Tundra Rhino + Rat Pack just saved my rank-up game and I hit rank 5 with this deck. Loving it

Trogg Beastrager is a decent enough replacement for now if you can't unlock the second wing of Karazhan.

I would suggest you to get the 1400 gold and get it. But for now you can run Trogg Beastrager or a Ravasaur Runt instead. 
Trogg Beastrager definitively does have some synergy with Rat Pack and such on.

Deck is insanely good for this cheap of a deck. Went from rank 18 to rank 11 in no time on the account I was testing it on XD
Here are a few tips to help you guys out if you are having troubles playing this.

REPLACEMENTS: 
-Swapped 1 Hunter's Mark for Deadly Shot 
-Would only recommend replacing Leeroy Jenkins with Reckless Rocketeer.
Try to get all of the other cards because they are playing a pretty big role in the deck.

MATCH-UPS:

From my experience this deck is insanely good vs:
-Quest Hunter,
-Quest Mage,
-Quest / Other Shaman decks. Basically all of the new-meta aggro decks that take a longer time to complete the goal.

It falls behind against:
-Control Warrior
-Handlock Warlock
-In some cases, had issues against Pirate Warriors. Sometimes won, sometimes lost, might depend on how lucky you are on card draw.
And pretty much any control-focused deck with alot of taunts.

STRATEGY:
Basically, you need to gain presence on the board early starting from turn 1. While the enemy skips a turn to complete a quest, put the beasts on the board and follow up with if you draw a Crackling Razormaw or a Kindly Grandmother on turn 2. Continue playing on the curve and clear when you need to clear an enemy minion and hit face with hero power when you can. It will just end up working out. You have big finishers like Kill Command and Leeroy Jenkins (Reckless Rocketeer) which allows you to kill the enemy by the time they complete their quest.

MULLIGAN:
A 'perfect' starting hand depends on the class you are playing against. But usually the best one would be a 1 drop that you play on turn 1 (always mulligan for a 1 mana drop (Best 1 Mana Drop is Alleycat > Fiery Bat > Raptor Hatchling > Jeweled Macaw to play on turn 1, means if you draw two or more 1 drops, keep the best one from this order) and try to get a 2 drop in your starting hand as well.)
Best curve play you could do is Alleycat and then Crackling Razormaw on turn 2 for a nice adapt. You will be ahead of your enemy and they will have a tough time regaining board presence or finishing quest without worrying about taking damage.

What you think about -Volcanosaur + Savannah Highmane? Or give me replacements for Volcanosaur (Dusted the free golden one that I got)

You are supposed to play this as a more Midrange-ish deck as well. Not just go full on quest and hope you will finish it in time. Even if you did have alot of one drops and finish it you would run out of steam very fast vs control decks.

This will definitively turn out to be on the stronger side of Hunter decks. Reason is - it has a more Midrange theme. The pure Quest Hunter like Trump's deck if faced against any type of control deck , it just loses way too fast. I love it.

I always thought that knuckles was an echidna...

HARAMBE!!!