The Rolling Pin is a Otherkind weapon, and as such, will either slot into your Otherkind Strife Specibus or create a new one. Attempting to equip the Rolling Pin when your Strife Specibus has four other specibi will result in the weapon being captchalogued.
Obtaining
The Rolling Pin can either be created using a Cruxite dowel from the Explore Antheum tab while in Sburb.