What you are looking at above is called Lichtenberg figures and it happens when a person is struck by lightning. The name comes from the German physicist Georg Christoph Lichtenberg who studies fractals caused by electrical discharge. He noticed that when lightning struck something, it always discharged in a fractal manner... In other words as all the electricity was trying to dissipate, it branched out and branched out and branched until the charge was gone. He studied this on insulated objects and the ground, but later it was discovered that it happened in people too!