This necklace has simply carved wooden beads strung on a thick rawhide strap. Each bead seems to have a different depiction of an animal etched into it.
As an action any beast wearing this necklace and capable of doing so can howl, shriek, or otherwise make an audible verbal noise, activating the necklace and causing an odd chord to ring through their cry. Each creature within 5 feet of the beast when it activates the necklace is strangely compelled to attack it. If it uses the attack action on its next turn and does not attack the beast or include it in an attack it takes 1d4 Psychic damage.