Hibernating Behemoth is a unit card.
How to Get
Beat the ninth mission in Jekk's Bounty, "The Collector's Horde".
By continually putting the card back on top of your deck to draw it, you can make the card bigger and bigger, while gaining you life.
This type of strategy synergizes well with Crown of Possibilities.
Hibernating Behemoth's artwork was reused from an earlier version of Dormant Sentinel, before its change in the Open Beta transition.