People look at a Christmas tree decorated with colourful lights at a residential compound in Beijing on December 8, 2017. (Photo by Nicolas Asfouri/AFP Photo)

A tourist train is decorated with Christmas lights in Bogotá, Colombia on December 10, 2017. (Photo by Jaime Saldarriaga/Reuters)

If we were to burn NH4Cr2O7 with HgSCN in the Dark Ages in Europe and show it to anyone, it is us who would be burning next on a fiery cross of Inquisition. And it’s no wonder, since this experiment produces a truly marvelous result. At first, as you ignite the mixture of NH4Cr2O7 and HgSCN, all you can see is that it is slowly burning with a reddish flame. After a while, however, a crater is formed in the middle of the burning pile, and then, suddenly, tentacle-like appendages start sprouting from the burning mixture. And you can almost hear the scream of the mad occultist – “Come forth, Kraken! Come forth!” But of course, this is simply a chemical reaction that is called the "Pharoah's Serpent". It was also often sold in firework stores until people realized that it was toxic.

In this photo provided by Britain's Ministry of Defense, on Monday, March 4, 2024, F-35B Lightning jets are parked at a flight deck of HMS Prince of Wales aircraft carrier of the Royal Navy, under the northern lights (Aurora Borealis) near the coast of Norway, Sunday, March 3, 2024. (Photo by UK Ministry of Defence via AP Photo)

A woman takes pictures using her mobile phone on a deserted square decorated ahead of Christmas, in Pristina on December 7, 2020, during a government-imposed curfew from 7pm to 5am, as part of preventive measures against the spread of the Covid-19. (Photo by Armend Nimani/AFP Photo)

The Christmas tree is lit at Rockefeller Center in the Manhattan borough of New York City, New York, U.S., November 30, 2022. (Photo by Jeenah Moon/Reuters)

A visitor watches the exhibit “Enchanted: Forest of Light” at Descanso Gardens in La Canada Flintridge, California U.S., December 9, 2016. (Photo by Mario Anzuoni/Reuters)

People walk on the Patriarch's bridge decorated for Christmas and New Year celebrations with the Christ the Savior Cathedral in the background in Moscow, Russia, Monday, December 16, 2019. (Photo by Alexander Zemlianichenko/AP Photo)