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.

Mexican collector Pablo Perez, holds up a Star Wars R2-D2 toy while he displays a toy collection of Star Wars characters and items at his home in Monterrey, Mexico December 12, 2015. Perez has collected more than 3,000 toys and items from the Star Wars movie series over 10 years, local media reported. (Photo by Daniel Becerril/Reuters)

This undated handout image courtesy of the San Diego Zoo Wildlife Alliance shows “Pat”, a Pacific pocket mouse fondly named after actor Sir Patrick Stewart. A mouse named after “Star Trek” actor Patrick Stewart is officially the world's oldest in captivity, a US zoo has announced Pat the Pacific Pocket Mouse – the smallest species of mouse in North America – bagged the title when he hit nine years and 209 days old on February 8, 2023. (Photo by Ken Bohn/San Diego Zoo Wildlife Alliance via AFP Photo)

Patients from the Larco Herrera Psychiatric Hospital wear costumes in the likeness of the first governor and founder of the Inca civilization, Manco Capac, right, and his wife Mama Ocllo, during the hospital's Independence Day parade in Lima, Peru, Wednesday, July 22, 2015. The parade is held on the hospital's campus every year ahead of the Andean nation's official Independence Day celebrations on July 28. (Photo by Martin Mejia/AP Photo)

Ballerinas Kennedy George, 14, and Ava Holloway, 14, pose in front of a monument of Confederate general Robert E. Lee after Virginia Governor Ralph Northam ordered its removal after widespread civil unrest following the death in Minneapolis police custody of George Floyd, in Richmond, Virginia, U.S. June 5, 2020. (Photo by Julia Rendleman/Reuters)

People remove mud and rocks from their house after a massive landslide in Chosica, March 24, 2015. Seven people were killed and more were feared dead in Peru after a massive landslide buried parts of a town amid heavy rains, authorities said on Tuesday. Six were missing and 25 injured in the disaster in Chosica, some 30 kilometers (18.6 miles) east of Lima, said Alfredo Murgueytio, the head of the National Civil Defense Institute, Indeci. (Photo by Mariana Bazo/Reuters)

A suspected Vietcong is kicked by a Vietnamese soldier holding a rifle as another soldier attempts to tie his hands on October 22, 1965. The prisoner was one of 15 captured October 21 near Xom Chua when government troops raided in the plain of reeds area. Troops killed 43 suspected Vietcong and seized some arms. (Photo by Richard Merron/AP Photo)