The Spear of Melkor (4d6) (-12,+20)
Heavily cursed. -4 wisdom, stealth. Branded with venom. Provides resistance to light, dark, blindness, nether. Cannot be harmed by acid, electricity, fire, cold. Aggravates creatures nearby. Drains experience.
Min Level 65, Max Level 127, Generation chance 2, 20.0 lbs

(Angband 3.1.2v2)