Here, us authors, can post all of the ideas that we have for powerful artifacts/creatures and/or creations that we dont mind sharing with other Villanous authors.
Please take what you write seriously (no Pixie Dust wand stuff) and above all else, have fun while creating and imagining (or else )

Grogar's bell
Tirek's bag

Staff of the Mandragora aka Mandragora Staff: for certain alchemists the mandrake root is extremely useful (and deadly) plant that has the nasty habit of killing those that hear its scream, but if the root manages to grow a creature called Mandragora takes its place.
All Mandragora sapplings are different from normal plant life, in the sense that it has motor skills of its own. This walking plant will absorb via its mouth and magic the life force of those it encounters, once it has absorbed or consumed enough life force the sappling will grow into a much bigger beast

Flute of the Rat King aka The Piepers Flute: just like in the story, this flute (if played correctly) can and will control those lesser beings that hear its melody, but for those who truly know certain secrets can control other...more interesting beings.
The more attuned the player is with certain parts of nature itself (or other darker types of magic) can dominate and control other beings (whether alive or dead)
After all "in the end of ones life, we shall all dance to the same tune, that my friend is death"

2610730
What does Grogar's ball do?
I think I can figure out what Tirek's bag does (dark rainbow anyone?)

Grogar's bell is like the alicorn amulet but much more powerful

Offer's towel. An artifact said to be able to absorb all moisture in the area.

Baron Samedi's Pendant: this small pendant is hidden so well that nobody knows it's very existence, in the deepest most godforsaken places inside Tartarus the pendant recides... the problem is that only the dead are allowed inside, it's said that if the pendant is weared by something that has life it will be the vessel for one of the six elemental beings of nature and reality.
The master of putrification, controler of the dead and damned, lord of curses and hexes. Baron Samedi the embodiment of death

Phlegyas Gauntlet: another mystical object that's location isn't known by anyone. The gauntlet by itself emanates so much heat that it pulverizes everything it does contact with, but if the heat doesn't kill you, you will be able to be a vessel of another fundamental being of nature.
The master of fire, lord of all heat, controler of metals, gems and their crafts. Phlegyas The Black Dragon

Changing Phial of the Damned: Whosoever drinks of this phial shall be doomed to a Changeling's Fate, sustenance provided thru not love, but by flesh and blood of those the shape thou takes. Dangerous, shall this monstrosity become, for not only is thy shape taken, but thy memories and skills as well.

Long-lost vial of Blacklight, anyone?