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.

Carrion crows sit on poles around a field on the outskirts of Frankfurt, Germany, early Monday, June 26, 2023. (Photo by Michael Probst/AP Photo)

A worker covers mounds of rice with a giant hat-shaped bamboo cone in a field in Brahmanbaria, Bangladesh on September 21, 2023 after they have been dried in the scoring sun. (Photo by Joy Saha/Rex Features/Shutterstock)

A dragon dance takes place at Stonehenge, Wiltshire, where people celebrate the Chinese Moon Festival, or Mid-Autumn Festival, one of the most cherished traditional festivals in Chinese culture, symbolising family reunions, gratitude, and the appreciation of the full moon on Sunday, September 15, 2024. (Photo by Ben Birchall/PA Images via Getty Images)

Police cars are seen overturned in the street in the framework of a demonstration against Cuban President Miguel Diaz-Canel in Havana, on July 11, 2021. Thousands of Cubans took part in rare protests Sunday against the communist government, marching through a town chanting “Down with the dictatorship” and “We want liberty”. (Photo by Yamil Lage/AFP Photo)

A dog jumps into a swimming pool to retrieve a ball during the Chatsworth House Country Fair near Edensor, Britain on August 31, 2018. (Photo by Darren Staples/Reuters)

Passionate fans are doing something unique (wacky) to celebrate the World Cup. They’re getting the likeness of their favorite player shaved into the back of their head. Photo: England fan Joel Moore (23) has had a haircut featuring the face of World Cup star Theo Walcott by Daren Terry from Lotus Styling in Bognor Regis, West Sussex. (Photo by Southern News & Pictures)

Competitors take part in the annual Mud Madness event at Foymore Lodge on April 22, 2018 in Portadown, Northern Ireland. The adult version of the event includes two laps of an 8km course through 25 obstacles while the kids event is run over 2kms. The race is in it's eleventh year and is sponsored by McVities Jaffa Cakes and event charity partner Marie Curie together with other numerous charities and fundraising groups. (Photo by Charles McQuillan/Getty Images)