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.

A juvenile European starling hops from deer to deer eating insects. The white-tailed deer did not seem at all bothered by the bird - who can be seen cleaning it of ticks and bugs. The starling was one of a flock near the herd of deer in Sandy Hook, New Jersey, USA in the last decade of November 2025. (Photo by Erik Kessler/Solent News & Photo Agency)

Model airplane enthusiasts take part in an event at a model airplane field in Mamak district of Ankara, Turkey on December 30, 2021. Model airplane enthusiasts, each owns different sizes and types of aircrafts, have the opportunity to have fun while training. Weekend meetups also give them an opportunity to help each other on technical issues. (Photo by Dogukan Keskinkilic/Anadolu Agency via Getty Images)

Cosplayers (left to right) Oli Hazeldine (dressed as Princess Adora from the animated series She-Ra); Val Imms (Catra from She-Ra), and Lou Frewin (Raven from the animated series Teen Titans) travelling on a Jubilee Line train heading for MCM Comic Con at the ExCel London in east London on Sunday, May 29, 2022. (Photo by Yui Mok/PA Wire)

This photograph taken on June 4, 2022 shows fish vendor Somporn Thathom sitting at her stall as a passenger train passes through the Mae Klong railway market in Samut Songkhram province, around 80 kms (50 miles) southwest of Bangkok. Six times a day at the market, local customers and foreign tourists scramble into nooks and crannies while vendors calmly move their woven baskets of goods away from the tracks and close their umbrellas. (Photo by Manan Vatsyayana/AFP Photo)

Members of a newly-formed “Siberian Battalion” within the Ukrainian Armed Forces take part in a military training exercise outside Kyiv on October 24, 2023, amid the Russian invasion of Ukraine. A newly formed “Siberian Battalion” as part of the International Legion within the Ukrainian Armed Forces is made up of Russians who have come to fight against their fellow citizens. They were a varied group-both ethnic Russians with long-standing opposition views and members of minority ethnic groups. (Photo by Genya Savilov/AFP Photo)

Russian servicemen display military camouflage equipments during the joint military anti-terrorist command and staff exercise of the armed forces of the Shanghai Cooperation Organization member states Peace Mission-2021 at the Donguz training ground in the Orenburg region, Russia, 23 September 2021. More than 3.4 thousand servicemen from Russia, India, China, Pakistan, Tajikistan, Uzbekistan, Kazakhstan, Kyrgyzstan and more than 600 units of weapons, military and special equipment are involved in the exercise Peace Mission-2021. (Photo by Maxim Shipenkov/EPA/EFE)

Handlers control the giant puppet MOCCO during a special training session in Takamori, Nagano prefecture, Friday, April 23, 2021. Tokyo 2020 organizers created about 10 meter-tall puppet to symbolize the spirit of the people from the regions affected by the 2011 earthquake and tsunami. The puppet will travel from Tohoku to Tokyo in May to be in place for the games scheduled to open in July. (Photo by Koji Ueda/AP Photo)