It’s the compound that used to be used in those firework novelties called snakes. We’re talking about mercury thiocyanate (or mercury thiocyanide). Talk about an odd compound. When you burn mercury thiocyanate it seems to morph into this alien looking creature. Turns out that the burning of mercury thiocyanate not only produces a snake-like substance but also releases toxic gases.
The firework was sold in Germany under the name of “Pharaoschlangen.” Some kids ate the resulting “snake” after the thing was burned and died. The result was no more Pharaoschlangen. Good news is, some people didn’t heed the warning and there is a video on YouTube of mercury thiocyanate burning! Watch it below.