The Tzhaar-ket-em (also known as the obsidian mace and the TokTz-ket-em) is a one-handed weapon used by the TzHaar. Unlike other maces, it does not give a prayer bonus.
It is affected by the berserker necklace, receiving a 5% damage increase when the necklace is worn. For this reason, it may be worth taking into consideration the usage of this weapon over the Dragon mace despite the loss of the +5 prayer bonus, as it will output more damage.