I’ll continue with my weekend barrage of posts, this is one by Ed Greenwood and was a pretty straightforward conversion.
Trumpet of Doom
Very rare wondrous item
When the trumpet of doom is winded, all human, demi-human, and humanoid skeletons and corpses within a 60 foot radius about the horn will be brought into unlife, as per the spell animate dead. All of the undead will obey you without question, to the utmost of their ability.
The greater the number of undead animated, however, the shorter the time that they will remain active. If only one skeleton or zombie is animated, it will remain active for 60 hours under your control. If two are animated, they will be active for 30 hours, three will be active for 20 hours, and if 4 or more skeletons and/or zombies are activated, they will be animated for only 10 hours before they collapse again.
The undead created by the trumpet of doom may be commanded to “go down!” (at which they will disintegrate into dust) if the user of the horn wishes it; otherwise, the undead will serve until destroyed, dispelled, or their time runs out. Use of a trumpet of doom is not considered to be a good act, though sounding it to test its properties is not evil.
The trumpet of doom may only be sounded once per month. Using it more often will produce no results.