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.

Mongolian Chinese performs a traditional Chinese dance in front of the Olympic Rings located near the National Stadium, the main stadium for the 2020 Tokyo Olympic Games in Tokyo, Japan July 29 2021. (Photo by Androniki Christodoulou/Reuters)

Mei Hoshizuki and AZM compete during the Women's Pro-Wrestling “Stardom” at Korakuen Hall on September 28, 2020 in Tokyo, Japan. (Photo by Etsuo Hara/Getty Images)

Fumie Takino, 89, founder of a senior cheer squad called Japan Pom Pom, and other members pose for commemorative photos before filming a dance routine for an online performance in Tokyo, Japan, April 12, 2021. “It's dancing; moving your body is nice”, Takino said. “And the costumes are unbelievably showy. Some people join just so they can wear them”. (Photo by Kim Kyung-Hoon/Reuters)

A Japanese woman and her daughter leave Daikichi kimono rental shop Wednesday, June 22, 2022, in Tokyo's Asakusa area famous for sightseeing, before attending their family friend's wedding. Japan is bracing for a return of tourists from abroad, as border controls to curb the spread of coronavirus infections are gradually loosened. Yusuke Otomo, who owns the kimono rental shop, can barely contain his excitement. (Photo by Hiro Komae/AP Photo)

A dog walks on the street as it snows in Kyoto on January 25, 2024. (Photo by Philip Fong/AFP Photo)

El Salvador's Elisa Funes fixes her googles during the warm-up prior to swimming finals at the Pan American Games in Santiago, Chile, Monday, October 23, 2023. (Photo by Silvia Izquierdo/AP Photo)

An alpaca Satsuki looks at a pet dog at a park while Alpaca Fureai Land's staffs walk the alpaca during early morning in Tokyo, Japan on June 21, 2023. (Photo by Kim Kyung-Hoon/Reuters)