Prialt

Prialt is a new painkiller that is derived from the venom of cone snails. These animals spear their prey with rods that contain around 100 to 200 different poisons, which have been tested in clinical trials. Prialt, however, is the only one that is FDA approved. It is the most successful painkiller since morphine; in fact, it is 1,000 times more potent than morphine and doesn't lead to tolerance.

The snails can be found in the coral reefs, but climate change severely threatens this area. Plus, there exist some 500 species of cone snails, only one percent of which has been studied. So that's a whole lot of potentially useful neurotoxins.