1/29/2012 - Pharaoh's Serpent

    This reaction doesn't involve the mixing of chemicals, but instead an exothermic reaction when the compound is in contact with a significant enough heat source.  The compound needed for this reaction is Mercury (II) thiocyanate or Hg(SCN)₂, which is an incredibly toxic compound, so I advise you not to try this reaction at home, due to the toxic gases and the toxicity of the compound.  The reaction was discovered by Wohler in 1821 right after his first synthesis when he observed the winding, worm-like projections.