This is the Thijs Midrange Beast Druid w Deathwing he was playing on stream. It has more top-end than most of the other lists and uses the battlecry of The Curator to pull some more cards from your deck.
I think the midrange builds are a lot stronger than the more aggressive decks most people came out with when the new card Menagerie Warden was released.
This deck plays out a lot like a standard token druid list with the added threats of Deathwing, and Menagerie Warden copying minions like a Stranglethorn Tiger or Druid of the Claw.
Mulligan Guide for Midrange Beast Druid
As a Druid ramp is always good so never turn away Wild Growth or Innervate. But ideally you want to curve out well too, so Enchanted Raven on turn one is ideal, and with no real 3 drop minion you want to ramp there into Violet Teacher + Spells.