A human with two different sets of DNA is called a chimera, and it’s more common than you might think. Most chimeras don’t even know they have this strange phenomenon going on inside them. You could be a chimera, and so could I. As we go along, take note of the interesting tidbits you could twist into a plot to add conflict. Without any help from the scientific community, the process of becoming a chimera occurs naturally. Numerous books and movies explore chimerism using a killer who’s had a bone marrow transplant or blood transfusion. But are these characters based in fact?