Orcus Figurine

From Candlekeep Mysteries, page 44.

Description
Wondrous item

Carved from an ogre's petrified heart, the gray figurine depicts the Demon Prince of Undeath in ghastly detail, clutching his skull-topped wand in one hand and three severed heads by the hair in the other. The figurine smells like decaying flesh, and this scent is detectable out to a range of 5 feet.

The figurine is a Tiny object with AC 17, 3 hit points, and immunity to all types of damage except radiant damage. A Detect Evil and Good spell or similar magic reveals that the figurine has been desecrated. As long as it has at least 1 hit point, the figurine has the following magical properties:
 * Undead within 30 feet of the figurine can't be turned.
 * Dead creatures within 30 feet of the figurine can't be brought back to life.
 * A creature that holds the figurine while praying to Orcus for at least 1 hour has a 10 percent chance of summoning a smokey avatar of the demon lord. Once this avatar is summoned, it can't be summoned again for 30 days. Orcus's avatar has the statistics of a wraith except that it's chaotic evil. It attacks all non-undead creatures it encounters, and it disappears after 1 hour or when reduced to 0 hit points.