The Metal Boomerang of Beor (4d5) (+8,+12)
A strange curved leaf-shaped piece of wood, its "forward" edges enhanced
with metal blades.
Beor's boomerang makes its wielder as agile as the winds, and as hard to
harm.
It increases your dexterity and speed by 4. It provides resistance to
acid, electricity, fire and cold. It cannot be harmed by acid, cold,
lightning or fire.
Level 20, Rarity 10, 2.0 lbs, 40000 Gold

(T.o.M.E. 2.3.5)