Gangers come and go, really good weaponry you’ve got to hang onto. Harlo the harpoon launcher has passed through many hands over the years. Just as Spike the harpoon has passed through many enemies through those same years.
Allegedly Spike and Harlo have been together for centuries an indomitable pair piercing their enemies and dragging their enemies back to their dooms (as though being impaled by Spike wasn’t pretty dooming to begin with).