Cone shell. Shell of a Mediterranean cone snail (Conus ventricosus) on the beach. Cone snails are highly venomous, predatory, marine gastropods that capture their prey using a long, harpoon-like, modified tooth (radula). The harpoon is launched out of the mouth on an extendable proboscis, and injects a powerful neurotoxin (venom), which instantly paralyses the victim. The sting of small cones is not fatal to humans, but that of some of the larger, tropical species, such as the Textile cone (Conus textile), can be. Some cone snail neurotoxins (conotoxins) have pain relieving properties that may provide a non-addictive painkiller (analgesic), 1000 times as powerful as morphine.