Hand of Fate 2

This is as straightforward as it sounds. Kill 50 Goblins in combat total to unlock this. Many new encounter cards that features Goblins were added that really helps speed this up. The best one I found was called Payment Due. Goblins are also very susceptible to Rethgar's Quake Artifact followed by a finisher.

Other encounters including Goblin Hunt and Gnome Hunt. The Goblin suit is called Mischief.