This is the Spirit Claws HS Shaman Card that is being released as part of the new adventure One Night in Karazhan. It’s a weapon for Shaman, and the card reads: Has +2 Attack while you have Spell Damage.
The spell damage totem is the most obvious way to activate this + damage, or Azure Drakes. Otherwise we need to build decks with more spell damage minions in to activate this weapon.
I like the design and at 1 mana this is a cheap weapon if you can use it when activated.