Once Waxadred dies this becomes 5 mana 4/4 summon a 7/5 and draw a card. That's insanely good. A dedicated Waxadred deck is suddenly a lot less sketchy. It'll be way easier to overrun them with 7/5s when you can summon them easily with this.
I play a lot of meme rogue and this doesnt look very good. If you go through the excrutiating pain of getting stuff in your deck while not dying and you play this to retrieve it, it better be game winning. Zephrys is tempting with Lab Recruiter but its still ridiculously slow for cards you already are paying a premium of 2 each time for.
Shadow of Death'ing an opponent's big minion then playing this immediately sounds really fun though.
This card is absolutely amazing in the correct deck. In particular, if you combo it with Lab Recruiter, it essentially lets you add two copies of a minion to your hand while adding 7/6 in stats to the board for 7 mana. If you do this on a powerful swing minion, this will let you get extremely large amounts of value in a pretty controlled way.
This card also provides an amazing combo with Leeroy Jenkins and Shadow of Death. Hit them in the face with Leeroy and shuffle three shadows into your deck, then play this minion to instantly summon 2 copies of Leeroy for 5 mana (with no whelps because it is a summon) and follow up with dome direct damage spells (Cold Blood or Eviscerate). With just the three Leeroys, you are dealing 18 damage over two turns, which is typically enough to finish a game if you are playing tempo rogue.