Parahumans are hypothetical, heavily modified humans, most often referring to hybrids of humans and other species. Parahumans are most likely to be created using synthetic biology techniques of genetic engineering, but may also involve chimera technology, which mixes distinct populations of cells into a single embryo.
American president George W. Bush spoke out against "human-animal hybrids" in his 2006 State of the Union address. In 2005 the US Patent Office rejected a patent application by Stuart Newman, backed by anti-biotech activist Jeremy Rifkin, on a human-animal hybrid.  This application was intended not to commercialize the technology but to call attention to and ultimately suppress it. 
Technically such hybrids already exist; for example, faulty human heart valves are routinely replaced with ones taken from cows and pigs. This surgery effectively makes the recipient a human-animal chimera, though there is no visible effect. Scientists have also done extensive research into the combination of genes from different species. e.g. adding human (and other animal) genes to bacteria and farm animals to mass-produce insulin and spider silk proteins. Note that individual genes can be transplanted between species without the transplantation of whole cells.
Resource from wikipedia