A man dressed as Santa Claus lights a Christmas tree on City Hall square in Copenhagen, Denmark, on November 27, 2022. (Photo by Sergei Gapon/Anadolu Agency via Getty Images)

A group of volunteers dressed as elves and a man dressed as the grinch take part in a Christmas celebration organised by the NGO “Unos Venezolanos” in the neighbourhood of Petare, in Caracas, Venezuela on December 21, 2022. (Photo by Gaby Oraa/Reuters)

The Borealis in the second decade of December 2023 gets ready to leave Liverpool for the Classic Christmas Markets cruise. It will call at Zeebrugge, Amsterdam and Hamburg to take in some of Europe’s best festive markets. (Photo by Bav Media)

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 handout image provided by Parks Australia, thousands of red crabs are seen walking in a drain on November 23, 2021 in Christmas Island. The annual migration of red crabs begins with first rains of the wet season on Christmas Island, usually around October or November. Millions of the red crabs make their way across the island to the ocean to mate and spawn. (Photo by Parks Australia via Getty Images)

People explore the ice covered pier in Port Stanley, Ontario, Canada, on December 27, 2022. The ice formations were created by a large winter storm which hit the region on over the Christmas weekend. Temperatures were expected to moderate across the eastern and midwest US on December 27, after days of freezing weather from "the blizzard of the century" left at least 49 dead and caused Christmas travel chaos. (Photo by Geoff Robins/AFP Photo)

Actors dressed as Father Frost perform in the main building of the Domodedovo airport named after Mikhail Lomonosov in Moscow, Russia, 27 December 2021. Russians are preparing to celebrate New Year's Eve on 31 December and Christmas which is observed on 07 January, according to the Russian Orthodox Julian calendar, 13 days after Christmas on 25 December on the Gregorian calendar. (Photo by Sergei Ilnitsky/EPA/EFE)

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)