Ward Against Wild Appetites

Seventeen animal teeth of various sizes hang together on a simple leather thong, and each tooth is dyed a different color using pigments from plants native to old-growth forests. When a beast or monstrosity with an Intelligence of 4 or lower targets you with an attack, it has disadvantage on the attack roll if the attack is a bite. You must be wearing the necklace to gain this benefit.

Source: Vault of Magic · OGL-1.0a · 5.1