A weapon/fishing tool and a variant of harpoon. As its name implies, it (typically) fires harpoon at a target to either drive it away or to restrain it with a tied rope on the other end of the harpoon to prevent them from escaping.
While there exists a harpoon gun that doesn't fire an actual harpoon (as some fire an explosive projectile instead, similar to an actual cannon). For tagging purposes, this tag is specifically refers to the "traditional" harpoon gun that fires harpoon, as such, apply this tag when the harpoon is visible on the device.
This tag implicates harpoon (learn more).