Ovu Mobani mask

From the third season episode: Dead Man's Party

Overstock from Joyce's Art Gallery causes her to decorate her bedroom with pieces from Africa. One piece in particuler, a mask, turns out to be Ovu Mobani (which means "Evil Eye")

a demon god of the undead.

It also happens that a party is being thrown for Buffy by her friends and Mother to celebrate Buffy's return from having run away at the end of Season Two and with the mask animating animals and people as zombies, wackyness ensue's. The zombie that can reach the mask first and put it on will become the living embodiment of the Zombie God who can stun people with a flash from it's "Evil" eye's.