This is the Avian Watcher HS Card released as part of the hearthstone adventure One Night in Karazhan. It’s a neutral card costing 5 mana with 3/6 stats.
The card reads: Battlecry: If you control a Secret, gain +1/+1 and Taunt.
It’s another card with secret synergy like the Mage card Medivh’s Valet. If you have a secret at the time of playing this minion it will be a 4/7 with taunt. That’s decent for 5 mana and will feature in control decks or Reno lists.