burning mercury thiocyanate looks something like indian Fireworks called black snakes

Black Snakes also called "Pharaoh's serpent" a version of firework i came across the below video in youtube which remebers me of a type of fireworks used in india called havu Mathre in Kannada( Indian Language) which produces a snake kinda ash while burning though before mercury thiocyanate was used as a chemical for the firework now it is replaced by Sodium bicarbonate which produces carbon dioxide gas and sugar forming carbon containing ash because mercury thiocyanate produced toxic gases while burning....

below clip shows the burning of mercury thiocyanate



i dont know whether any body outside india has used fireworks something like this but in india almost all the kids play with this kinda firworks..