"Surprise!"

Reader-added tags include "Not like passing gas", "No comfort in suffocation", and "Don't you know? You die."

Hydrogen sulfide was a suicide fad years ago in Japan. It'd be around the time Puella Magi Madoka was coming out, because that series actually referenced it with a suicide cult mixing bath products, which was how people were making it. It is not a pleasant choice and leaves a serious chemical hazard for others (because people were doing it inside enclosed spaces to get the concentration needed).

H2S acts on you like HCN (hydrogen cyanide) by blocking the oxygen transfer in your cells. The REAL danger is, that it has the typical smell of rotten eggs only in low concentrations. In deadly concentrations you won't smell it. You just die!