The berbalang was a biped, gaunt and lanky. It had leathery skin, which was black in color. It had wide eyes, which glowed and were white. Their eyes could see in the dark. They had a pair of broad, bat-like wings on their back. These allowed the berbalang to fly and could do so with speed and agility. It had very sharp claws and needle-like teeth.
The berbalang used its ability to fly to give it an advantage during combat. It used it claws and teeth as weapons. Its projection was immune to charm, hold, and sleep spells. The projection would attempt to flee combat if it was struck. If the projection was killed, it was likely that the physical body would also be slain.
Most of its life was spent in a coma, with its spirit wandering the Astral Plane. Its spirit would stalk other astral creatures. The berbalang had a complex ritual for courtship and mating. Its only food was freshly killed human flesh. It returned to the Prime Material plain to feed, once a month on the full moon, usually for three days. It would find a suitable lair and then would manifest an exact duplicate of itself, a projection. This projection could roam up to three miles from the berbalang's physical body 
If the projection killed a human, it would bring the corpse to the physical berbalang, the projection feeding off the body while in flight. The berbalang's hunger was usually satisfied by the time the projection returned with the body.
The berbalang chose a new lair every three to four months to avoid detection.
- ↑ 1.0 1.1 Mike Mearls, Jeremy Crawford (May 29, 2018). Mordenkainen's Tome of Foes. In Kim Mohan, Michele Carter eds. (Wizards of the Coast), p. 120. ISBN 978-0786966240.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 David Cook, Steve Winter, and Jon Pickens (1989). Monstrous Compendium Forgotten Realms Appendix (MC3). (TSR, Inc), p. 9. ISBN 0-88038-769-6.