Great adition to DK! Besides taht, I will put a copy on Reno Hunter for sure, it can be buffed and add a nice amount of heal early, since it heals when attack and may force an aggro apponent to waste damage killing it.
The first thing I thought of when I saw this card: Quest Rogue. This card is why they nerfed it.
Pretty sure they nerfed quest rogue because people found it oppressive and un-fun, not because of a future minion which is effectively 2 mana heal 1 and deal 1 to a minion (which has to do less than 3 damage or the minion dies and can't be bounced).