This is Venus, she's a Chimera cat and technically, her own twin! She's the result of four parent cells (two fertilized eggs or two embryos fused together). The two separate organisms had already started to develop, so that's why some features of both remained in this one amazing kitty!
Venus is most likely a "chimera" -- an animal composed of two populations of genetically distinct cells that originated from different zygotes. This means one would have two different sets of DNA. She is also, relatedly, heterochromatic -- her eyes are two different colors.