So all types of dogs are human created by centuries of breeding. Ligers, mules, Tions are all examples of animals which are made by mixing two different animals but all of them have problems giving birth.
All sorts of experiments are being done to understand DNA and genetics better. Given enough understanding, one day we could possibly mix many different species together successfully. When it comes to humans, it’s more difficult because experiments on humans would presumably need to be done which could be very unethical. (I still think a lot of these experiments on animals are unethical!)