Twinzy is a “half sider” budgerigar, also known as a parakeet. Probably one the of the best ever photographed. Twinzy has the characteristics of a blue bird on one side and a green bird on the other, even his tail feathers are split down the middle
A chimera (also spelled chimaera) is a single organism composed of genetically distinct cells. This can result in male and female organs, two different blood types, or subtle variations in form. Animal chimeras are produced by the merger of multiple fertilized eggs. In plant chimeras, however, the distinct types of tissue may originate from the same zygote, and the difference is often due to mutation during ordinary cell division. Normally, chimerism is not visible on casual inspection; however, it has been detected in the course of proving parentage.
Another way that chimerism can occur in animals is by organ transplantation, giving one individual tissues that developed from two different genomes. For example, a bone marrow transplant can change someone’s blood type.