Here's my current Jungle Giants OTK deck.  It's really fun, but it's still a MEME deck. So please CRAFT CARDS AT YOUR OWN RISK!  But yeah, so far I've climbed from Platinum 5 to Diamond 6 quickly.

I didn't create this OTK.  I just tweaked it a little for today's meta.  I haven't even tried any new cards yet (from Scholomance Academy).  But so far I've had success with this one.  I'll provide a write up soon to help out. 

Basically you try to complete the quest quickly.  Play Barnabus the Stomper, then draw some 0 cost minions.  The combo is to play (all in one turn) Charged Devilsaur, Carnivorous Cube, Faceless Manipulator and/or Gloop Sprayer, then Deathwing to destroy the cubes and create a bunch of Charged Devilsaurs which can immediately go face!!  Yeah, it's FEELS GREAT!!

Now, you may think this is way too "high roll", but there are a lot of different ways to make the deck work based on how many and which 0 cost minions you get.  I'll add card explanations later.  I gotta test more.  gl