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.

Aubrey Zimmermann, 9-months-old, poses for a photo with Santa at the Willow Grove Park Mall ahead of Christmas in Willow Grove, Pennsylvania, U.S. December 3, 2021. (Photo by Hannah Beier/Reuters)

Russian riot policemen beat young PREGNANT female anti-Putin activist during a protest rally against the Presidential inauguration of Vladimir Putin on May 6, 2012 in Moscow, Russia.

A BYU fan show his support during the first half of an NCAA college football game against Oklahoma, Saturday, November 18, 2023, in Provo, Utah. (Photo by Rick Bowmer/AP Photo)

Revellers gather for the start of the Annual SantaCon Bar Crawl at Father Duffy Square, a section of Times Square, on December 14, 2019, in New York City. SantCon is an event where people make donations to charitable causes and dress up as a Christmas character and visit bars around the city. (Photo by Steven Ferdman/Getty Images)

A diver dressed in a Santa Claus costume swims at the Lotte World Aquarium in Seoul, South Korea, Monday, December 23, 2024. (Photo by Ahn Young-joon/AP Photo)

A Police officer reacts to protestors outside the Piet Retief Magistrates court where the five accused in the shooting of the Coka brothers on the Pampoenkraal farm appeared, Mhkondo, Mpumalanga, South Africa on April 19, 2021. (Photo by Jacques Nelles)

A monument with old MiG fighter jet is seen next to a damaged civil infrastructure building at the site of a Russian military strike, as Russia's attack on Ukraine continues, in Vinnytsia, Ukraine on July 14, 2022. (Photo by Valentyn Ogirenko/Reuters)