Horn of Baator (3.5e Equipment)
From D&D Wiki
Horn of Baator: A smooth black horn with no blemishes or marks discernible to the naked eye, however if looked at by the light of arcane or infernal fire an inscription is written on it in Dark Speech. In this primordial tongue, the inscription says, "The fiendish answer the call of the Lord of the Ninth"
Usage: Whoever picks up this horn must make a Will save (DC 25) or become evil aligned. Blowing the horn acts as Summon Monster IX only summoning Fiends, Devils, or Demons. The beings summoned are randomly chosen by the DM and can be one creature from the creature from the 9th-level list, 1d3 creatures of the same kind from the 8th-level list, or 1d4+1 creatures of the same kind from a lower-level list. The Horn can only be used 1/week.
Discerning the nature of the horn requires a DC 30 in Knowledge: Arcana, Religion, or the Planes. The writing cannot be read unless under arcane or infernal fire light and the reader knows Dark Speech.
History: Created near the time of the signing of the Pact Primeval, the Horn of Baator was used by Asmodeous to control the chaotic hordes of devils and demons in the Nine Hells. Some time after the Nine Hells were settled, the horn faded into legend among the inhabitants. According to the legends among the fiends, the Horn can only be destroyed by being crushed under the boot by an uncorruptable hero who has been touched by the divine. Some Demonologists who have researched the Horn believe this means only a follower of a lawful good deity, who has encountered said deity, can destroy it.
Strong Conjuration; CL 20; Weight: 2 lb.