Nabassu are creatures spawned in the Abyss but nurtured on other planes, where they grow and gain power by slaying and devouring humans. They communicate using telepathy.

Nabassu, unmistakably fiends, are gargoylish in appearance, standing 7’ tall. They are gaunt with leathery wings, tightly corded muscles, long claws on hands and feet, steely gray eyes, and a wide mouth lined with sharp fangs.

Combat: Nabassu go through two distinct phases, fledgling and mature, that have different combat abilities. However, in both phases the nabassu can attack with two claws (2d4 damage each) and bite (3d4 damage). They can attack with magic but prefer natural attacks, especially against a helpless enemy. These create greater terror in the victim and, therefore, greater pleasure for the nabassu.

Fledgling

Fledglings begin life with AC 4 and 7 Hit Dice. When they enter another plane (usually the Outlands or the Prime), they gain 2 more hp. Each victim killed and eaten on the foreign plane adds 1 hp and a “half factor“ of AC. For example, a fledgling that devours two humans would have 7+4 HD and AC 3. After 18 meals it reaches full growth (AC -5 and 7+20 HD).

Immature nabassu do not gain the spell-like abilities available to other tanar’ri but have the following spell-like abilities: darkness, 15’ radius and its death gaze (once per day). The death gaze forces the target to save vs. spell or transform, over 10 days, into a ghast (or ghoul if the victim is a demihuman). The death of the nabassu or a remove curse spell reverses the process, but once the process is complete, the change is irrevocable.

Immature nabassu also have some thief abilities: move silently (40%), hide in shadows (50%), detect noise (55%), and backstab (×2). They are affected only by attacks from magic or cold-wrought iron weapons. Nabassu have Strength 19 (+7 damage adjustment).

Mature

At full growth, nabassu lose their fledgling abilities but gain those spell-like abilities available to all tanar’ri, plus the following spell-like powers: energy drain (by touch), regenerate (1 hp per hour), silence, 15' radius, and vampiric touch. Three times per day, a mature nabassu can attempt to gate in 2-20 manes, 2-5 cambions, or 1 mature nabassu with a 45% chance of success. When in the Abyss, mature nabassu can automatically summon 2-5 ghasts once per day. Mature nabassu can become ethereal at will, twice per day. Also, any living creature coming within 10’ must save vs. paralyzation or he paralyzed for 1d10 rounds (once per encounter). Mature nabassu have the same Strength and immunities as fledglings.

Habitat/Society: Nabassu are a scourge of humanity. They are the only fiends that live a part of their lives on a foreign plane. Unlike other tanar’ri, nabassu seem to have no place in the Blood War. Once they return to the Abyss from their tour of carnage on the Prime Material, they will reside in one of the fortress of the Abyss for the rest of their immortal existence.

Ecology: What role these monsters play is unknown. Perhaps the slaying of humans and spilling of innocent blood somehow bring the tanar’ri power.