The Demon Core meme refers to a 6.2-kilogram subcritical mass of plutonium that was involved in two fatal criticality accidents at Los Alamos Laboratory in the 1940s. The most iconic imagery associated with it involves physicist Louis Slotin performing a 'tickling the dragon's tail' experiment, where he used a flathead screwdriver to prop open a beryllium shell. Internet culture has transformed this terrifying moment of scientific history into a metaphor for high-stakes situations, precarious balance, and the 'forbidden snack.' It is widely used to represent a person poking at a problem that could explode at any moment, often accompanied by jokes about the lethal 'blue flash' of ionizing radiation that occurs when things go wrong.