This is the Curious Glimmerroot HS Priest Card from the Journey to Un’Goro expansion due for release in April.
It’s a Priest class minion and the card reads: Battlecry: Look at 3 cards. Guess which one started in your opponent’s deck to get a copy of it.
You can get Curious Glimmerroot by opening packs from the Journey to Un’Goro set.
*A new mechanic we have not seen before at the time of release, interesting and fun ‘guess mechanic’.