AKA the "wolf brush" or "wolf bamboo" or "multiple tipped bamboo spear". A branched, multi-tipped spear with blades attached to the branches. The blades could be dipped in poison. 

It was probably an invention of the Chinese general [[Qi Jiguang]] of the [[Ming Dynasty]], who described it in his manual titled Jixiao Xinshu. The manual describes that the lang xian acted as backup for the [[rattan shield]] bearers in a "mandarin duck formation". In Korea, the weapon was known as nangseon and where Joseon received training in its use from Ming during the [[Imjin War]].
lang xian (weapon)