Image added for reference.
This appears to be what happens when ammonium dichromate ((NH4)2Cr2O7) and HgSCN (I don’t know the compounds common name, but it’s a bond of mercury, sulfur, carbon, and nitrogen) is ignited.
The ammonium dichromate is the initial “volcano” reaction, while the HgSCN appears to be what causes the “tentacles.”
Here is the original video this GIF was made from: Chemische Reaktion NH4Cr2O7 mit HgSCN
no shut up they summoned satan
hOLY FUCK
And people wonder why I’m a Chemistry major.
Yup, traditionally the reaction’s called the Pharaoh’s Snake and was available to buy as a firework in some places. Well, until they decided it was a bad idea to sell people fireworks that incorporated mercury compounds.