Required: fire-resistant surface, sand, squeeze bottle with ethanol, spatula, pincette, "Emser Pastillen" (mixture of baking soda and sugar)

Procedure:

4-5 tablets per "snake" are required. Give them into a Petri dish and add 100% ethanol for soaking.
Form from the sand a "mountain" and press on the top to form a "crater". Put some ethanol into the crater. Give the soaked tablets into the crater and again add some ethanol.
As a catalyst a small amount of ash (from a cigarette e.g.) is added and the tablets are ignited.

Explanation:

In the heat sodiumhydrogencarbonate disintegrates under formation of CO₂. Together with the molten sugar a voluminous foam is produced. Part of the sugar is combusted under formation of coal.

In Bad Ems there´s a hot spa whereby "Emser Salz" is found naturally.