Berserker Axe
Weapon (any axe), rare, requires attunement · 2014 rules, SRD 5.1
+1 attack and damage; +1 HP per level while attuned. Curse: when hostile creatures damage you, DC 15 Wis save or go berserk, attacking the nearest creature.
Also in the 2024 rules (SRD 5.2).