In the 8th century AD, it was recorded that the poison of "death smile" originated in Sardinia in the Mediterranean, and the local people executed the death penalty by making prisoners drink this poison. According to a new study, the elderly and prisoners who lost their ability to take care of themselves on the ancient island of Sardinia will laugh after drinking this mysterious drug and eventually fall off a cliff and die.

This poison is completely different from the poison gas used by Batman's nemesis. "Death Smile Poison" is a plant-based medicine. The research results were published in the Journal of Natural Products. Researchers speculate that this plant can be used to eliminate wrinkles in the cosmetics industry.