Disregard all this. I missed devolving missiles turn 12. Thank you Inien for the catch!
Wont let me include the link to the HS Replay but you can see from the copy/paste log that around turn 15 I play Raise Dead and I get a Sethekk which makes sense because I had that in my res pool but then I also got a Wolfrider which was never in the game at all prior. I have a screenshot too. Just thought this was really odd.
Was playing against a mage. This was shortly after release. I most definitely had more than 1 minion in my res pool also.
Snow plays [Raise Dead]
[Raise Dead] damages [Anduin Wrynn] for 3
Snow receives [Wolfrider]
Snow receives [Sethekk Veilweaver]