Seventeen was an artificial lifeform, a product of genetic engineering, brought into existence by "Doctor," a repurposed T-series tactical droid belonging to Passel Argente.
His genetic makeup was a chimera, incorporating genetic material from a minimum of three distinct species. Specifically, his head was that of a blarth, he possessed the tusks typical of a boma, and one eye characteristic of a cannok. The forelimbs were those of a boma, whereas the main body and rear legs mirrored those of a cannok. His tail originated as a boma's tail, but terminated in a blarth-like tip.