Monster Orb
From BlackTalon Wiki
Monster Orbs are a special kind of loot that you obtain after killing a special monster. The drop is guaranteed and it can yield you with several kinds of rewards, such as gold, upgrade stones and gear. The loot obtained from these monster orbs are greater if you defeat a stronger class of a monster and it can provide you with equipment pieces equivalent to the class of the monster you defeated, starting with the epic rarity. Check out Equipment Rarity for more information.
You can only obtain a monster orb from a skulled monster.