A chimera is a mythical creature from ancient Greek mythology, often depicted as a blend of different animals. Typically, it has the body of a lion, the head of a goat protruding from its back, and a tail that ends with a snake's head. Chimeras symbolize the idea of combining various elements into one, representing chaos and unpredictability. In modern science, the term "chimera" is also used to describe organisms that contain cells from two or more different genetic sources. This can occur naturally, such as in twins that share cells, or artificially, as in genetic engineering. Chimeras in biology help researchers study development and disease.