Question about a weapon:

I want my new Barbarian to start with a Kanabō, but I don't know what weapon it would be considered.

My initial impulse is Greatclub, but I feel the Kanabō is more of a Martial Melee Weapon. Would it be a Maul? Or a Morningstar, because the studs would do Piercing damage? Maybe a Warhammer? Does anyone know?