WotC just shared this Arcane Propulsion Arm! It functions as a 1d8-dmaage magic melee weapon which you can throw (don't worry, it flies back and reattaches).
The DMG has rules options for lingering injuries, with one of the options bejng losing a hand or arm.I think it raises interesting questions about what magical healing - like cure light wounds - actually DOES. Mechanically, a character cannot lose a limb in D&D (except maybe to a vorpal weapon or similar). But if we allow that dismemeberment can happen, would we allow a cure wounds spell - perhaps of high enough level - to restore a lost limb? Do we need regeneration for that?
Under what circumstances would a character actually end up with a use for this item?