Quick Edit:  Subbed out the two Hunter's Marks for a Tracking and Sphere of Sapience for the reasons mentioned in the card replacements section at the bottom.

Hello Hunters,

This is an amalgamation of several other Hunter decks I run and it's as greedy as possible :)

Basic Gameplan

If you go first:

• Survive early and draw down your deck via Questing Explorer, Scavenger's Ingenuity, and Diving Gryphon.
• Survive the midgame via Professor Slate, Swarm of Locusts, and Khartut Defender. 
• Start turning the tides with Nagrand Slam or Yogg-Saron, Master of Fate.  
• Those 10-cost cards Corrupt your Carnival Clown which finishes the Quest and sets up lethal next turn.

If you go second:

• Mulligan as hard as possible for Kael'thas Sunstrider
• By Turn 6 hope you draw 1 copy of Licensed Adventurer and 1 copy of Nagrand Slam
• On Turn 6 play the Coin you started with + the coin from Licensed Adventurer to drop Kael'thas and play a 1-mana Nagrand Slam
• Rejoice

Gameplay Tips

The mulligan was already outlined above in the form of card draw/early minions if you go first and Kael'thas + Licensed Adventurer + Nagrand Slam if you go second.  However, against aggro you may need to look for Bola Shot and Unleash the Hounds to survive long enough.  Other tips:

• The Professor Slate package is just Rapid Fire and Bola Shot so use those spells wisely.
     
• Hunter's Mark also synergizes with those spells, feeds Yogg, and finds willing sacrifices from Unleash the Hounds and Swarm of Locusts
     
• Diving Gryphon will always draw its other copy or Zixor, Apex Predator.  Those are also the only Beasts in the deck which means they're the only targets for Scavenger's Ingenuity and you can save one to pull/buff your Prime card later.
     
• The Khartut Defender package helps you stabilize against aggo and Jewel of N'Zoth can ensure you make it to Turn 10 once one of them dies.  Jewel is also a target for Kael'thas if need be.
      
• Don't be afraid to play an un-corrupted Carnival Clown on Turn 9.  3 copies will help stall things, progress the Quest, and may force out some removal for your 2nd corrupted clown later.
      
• There are 20 potential spells in this deck to feed Yogg, though only 18 guaranteed if you draw Licensed Adventurer after you finish the Quest.
      
• Rapid Fire used to be a nice Kael'thas Sunstrider activator, but now you have to wait until Turn 10 to pull off a combo which is still sometimes your best play.

Card Replacements

• This deck would definitely benefit from Tracking and/or Sphere of Sapience, so I might replace Hunter's Mark with either of those.  This deck was originally made early in the season when I was facing a lot of Libram Pallys and Hunter's Mark helped me survive all those buffed minions.
      
• I've also considered including Escaped Manasaber to help pull off Kael'thas combos, but it's never made the cut so far.  Could swap out Zixor for it so it's drawn pretty consistently from Scavenger's Ingenuity.

Happy Hunting!