This cat is what’s called a Chimera or a Chimaera. Though rare, it’s not unheard of to have an organism (usually an animal) to be composed of two or more sets of DNA. This particular cat shows this perfectly with her distinct differences in appearances on either side of her face and throughout the body. Although a Chimera is a single organism it can be accurately described as being one’s own fraternal twin.
This is Venus, a 3 year old chimera cat. Chimera cat is one individual organism, but genetically its own fraternal twin. A chimera is typically formed from four parent cells (either two fertilized eggs, or two early embryos that have fused together). When the organism forms, the cells that had already begun to develop in the separate embryos keep their original phenotypes and appearances. This means that the resulting animal is a mixture of tissues and can look like this cat.