I have a feeling this is the sleeper of the set. Maybe not for this expansion but in future I can see this becoming a problem with more buff cards added to the game.
Good stats and 5 health is a lot for a 4 mana stealth minion. Typically stealth minions have low health as a downside so that your opponent could at least remove with most AoE or random damage effects, but this stealth minion is pretty much guaranteed to live a turn to set up with buffs and cheese your opponent.
This is a staple in buff priest and might actually put the deck over the top.
I want this card in my Oaken Summons deck , its so cool, very good against aggro, helps with spellstone triggers(3armor), because of the stealth you can make the trades. Its like made for exactly that reason. So for example you can run Grizzled GuardianAstral Tiger deck, so you can go infinite. These and Ironwood Golems are good defensive tools, meanhwhile they keep thinning your deck. Also you run Carnivorous Cube and if you against aggro, you can easily eat this and get a bunch of armor after 2 of these Half-Time Scavengers slaughter their tokens. Its just get you to the lategame naturally.
If not this deck type, but it will find its place. I am sure of it.