I'm not sure what the story is here... Brann summons all the beasts of the forest to break open the vault door?

Anyway, this is an experiment that started because when playing Quest Hunter, I had problems refilling my hand. So I wondered if I could play Master's Call in this deck. You have to give up staples like Leeroy Jenkins, but playing with more cards in hand just gives you a lot more options in the mid-game.

So far, it's going pretty well. You can win with a Scavenging Hyena that goes out of control early on, or you can complete the quest and then any minions that stick to the board become deadly. Compared to the more standard quest deck, I think this is stronger in the mid game and a bit weaker in the late game, so whether it's worth considering on ladder probably depends on the meta. I played it around rank 14 and got more wins than losses, although I didn't keep accurate stats.

One card that pleasantly surprised me is Hunting Mastiff. It produces a lot of beasts from a single card plus it has rush so it's good removal and can be drawn by Diving Gryphon. 

I'm not sure about the secret package. Snake Trap is the reason for running it. Rat Trap makes life awkward for your opponent, especially when lackeys are popular. Having two copies of Rat Trap seems too much though, since if an opponent commits to playing around it, you'd be stuck with the second copy in your hand. Having only three secrets in total means it can be hard to get value from Phase Stalker and Hyena Alpha, so I added one Freezing Trap. But that is the secret I'm least confident about.

I considered cutting Phase Stalker, but it has decent stats for its cost and opponents often go out of their way to kill it, so even if you don't plan to use your hero power a lot, it still seems worth running. I usually just drop it on turn 2 or 3, preferably after setting up Snake Trap.

I also considered going in the opposite direction and playing more secrets and Subject 9. With four secrets it can already happen that in the late game there are no more secrets in the deck for Phase Stalker to pull, so to make Subject 9 playable you'd have to add at least two more secrets. Those other secrets don't really have much synergy with the quest: they delay your opponent, but by not progressing your quest they also delay you. So that didn't seem appealing to me.

A second Hyena Alpha might be worth it even with just four or five secrets in the deck, since it's just a lot of stats for its mana cost. But it is also a situational card and I prefer to have those as one-of, so I don't get stuck with two unplayable cards in my hand if the right situation doesn't arise.

I added Savannah Highmane because I felt that against slower decks I was too much all-in on Unleash the Hounds and hoping the opponent goes a bit too wide. Having a sticky minion with good stats allows you to be a bit more proactive. Maybe a second Highmane is even a good idea. I generally don't like having a lot of 6-mana cards because you can't play two of them at 10 mana, but this deck has a lot of cheap cards as well so it's less of an issue here.

I had the Clear the Way sidequest in an earlier version and while it's not hard to complete it, the fact you get the 4/4 a few turns after playing the card made it underwhelming in my experience. It might be something to consider if you start tweaking the deck though: maybe if you run two copies of Desert Spear you can consistently complete the sidequest quickly and then it is worth it?

All cards except the quest and Master's Call are either cheap or replaceable. If you don't have Snake Trap though, you might be best off cutting the entire secret package.