This is the Priest of the Feast HS Priest Card being released with the adventure One Night in Karazhan coming in August.
The card reads: Whenever you cast a spell, restore 3 Health to your hero.
This minion is a high health minion so it has a chance of sticking on the board allowing you to heal. It’s not a bad card on first sight, will see some play but it doesn’t look like it’s going to change Priest much.