Sheep Storm. Edit
In-game description of this Special Item Set for Heroes.
It's raining sheep! A large area gets bombed with sheep, dealing zone damage on every building in the area. The center of the area is the building you target. Beware, with Sheep Storm equipped you will only be able to target buildings.
To unlock Sheep Storm, you must Craft the 3 piece Goblin Set in the Hero Equipment Crafting area of the game using either Gems or a Free Item Master Craft that you have won.
Note: as said above, with Sheep Storm equipped on a Hero, that Hero loses the ability of free targeting. Targeting your Hero to a spot on the ground is impossible. Currently, the Goblin Set is the only ability set that removes the free targeting feature.
Cooldown of the Special Attack: 35 Seconds
Here is a Video by Corbell from August, 2015 - Sheep Storm Video Wiki.