The color of the ball tells you what effect is on the mob. There is also an Effect icon on the mob. Just in case you do not notice the energy ball or the icon, there is a sound that all these enhanced mobs make.
Only mobs that display one of these four effects have a chance to drop a Mysterious Bag.
increased hit points Takes more damage to kill, hits a little harder
+110%
The database lists the Mysterious Bag's HP ranging from 31,964 to 66,357 but there is no combat involved. The Mysterious Bag appears on the ground randomly, near the fight, as if the mob dropped it. Interact with the bag to open it. Loot it after to find a treasure!
Many players call these "Stat Bags" because the Accessories found inside are useful as a source of Runes (using a Purified Fusion Stone to strip stats out of them).
These bags (level 70 and up) can also drop a Transformed Recipe, which is needed to craft the completing pieces for many Item Sets dropped throughout the upper level zones of Taborea. Any listed Recipe drops on this page will be exemplar but not exhaustive as they are simply too numerous to ever list them all. If you have a few days to peruse a complete list of these recipes, try this link to the RoM-Welten database.
Being treated as an NPC, these Mobjects will remain in-game much longer than a normal drop. In areas where monsters fight each other, such as the Thornose Seagulls and Beach Woodworms on North Thornose Beach in Tergothen Bay, a dozen of these bags may litter the ground and may be picked up by any passerby.
The bag may contain any or all of Festival Items, Amulet of Light, and one or more of the items, by zone, from the table below. Most Mysterious Bags have the same structure to their Drop Table:
Purified Fusion Stone to strip stats out of them).
Amulet of Light, and one or more of the items, by zone, from the table below. Most Mysterious Bags have the same structure to their Drop Table:
Coin of Petals (30 Days) (including this bag). Since the monster and the bag both have one, this is worth 
