This is the Jade Blossom HS Druid Card from the upcoming expansion Mean Streets of Gadgetzan.
It’s a Druid class spell and the card text reads: Summon a Jade Golem. Gain an empty Mana Crystal.
Jade Golems are minions that each time you summon one it’s stats will increase by +1/+1. So, your first Jade Golem is 1/1 as per below, then 2/2, and so on.
You can get Jade Blossom by opening packs from the Mean Streets of Gadgetzan set.