The Two-Handed Great Flail 'Thunderfist' (4d6) (+5,+18)
+4 strength, constitution. Slays animals, orcs, trolls. Branded with lightning, flames. Provides resistance to lightning, fire, fear, dark. Cannot be harmed by acid, electricity, fire, cold.
Min Level 45, Max Level 127, Generation chance 3, 30.0 lbs

(Angband 3.1.2v2)