This small, thin object is pointed on either end, with a grip in the center. It's made of a material that looks like silver but is springy and resilient - to the knowing eye it is immediately identifiable as goblincraft, marking it as a foul object. In the hands of a Small creature it can be wielded like a melee weapon - in larger hands it isn't very effective this way and works better as a javelin.
Trained goblins know how to use the magic properties of the Spine, but for most it is random. If it strikes a target, it will always unleash a point of electrical damage and absorb a point (but only from living creatures. Constructs, undead, or anything else lacking a central nervous system can be shocked but can't also be drained). It will absorb an additional point each round until withdrawn. In other words, a strike does whatever physical damage the Spine does (1d4) + 1 point of shock + 1 point is stolen if possible.
The absorbed HP is stored in the Spine, to be released as shock damage in a 1/1 ratio. Those trained in its use, or who study it long enough, learn to control this so they can strike without releasing HP (to store more of a charge), and even control how much HP is released in order to cause more damage or hold back in order to incapacitate.
Whenever a thrown Spine hits with a natural 20, it has tapped directly into the nervous system of the target. It goes apeshit.
