Since you seem to have a knack for both magic items and musical tie in's, how about Maxwell's silver hammer?
Bang bang Maxwell's silver hammer came down,
Upon his head.
Bang bang Maxwell's silver hammer,
Made sure that he was dead.
I had an old DM who had an NPC Maxwell with said hammer, but all it did was stun on a critical. I'm pretty sure you can come up with something more interesting, and fairly low cost (it was a 3-4th level campaign in 2nd edition).
Bang bang Maxwell's silver hammer came down,
Upon his head.
Bang bang Maxwell's silver hammer,
Made sure that he was dead.
I had an old DM who had an NPC Maxwell with said hammer, but all it did was stun on a critical. I'm pretty sure you can come up with something more interesting, and fairly low cost (it was a 3-4th level campaign in 2nd edition).