|Cause of Death||Sprayed by hydrochloric gas|
|Killed by||Dean, Dr. Bruce Abbot|
|Family|| Patrick Ross † (Father)|
Unnamed prostitute † (Mother)
Various Siblings †
|Abilities||Transform to alien form, Strong animalistic instinct of procreation, Rapid regeneration, Penis-tentacle for impregnating females or killing|
|Played by||James Leo Ryan|
Yosef was riding in a train when Sara feels his presence and tries to reach him. But she falls and gets her arm cut, however he has felt her too.
When Sara realizes that he is town, she goes to a hotel where she waits for him. Once Yosef arrives and checks in the two begin to mate, but then Sara rejects him when she discovers that he suffers from diseases. This enrages him and Yosef tells her not to turn her back on them (the halfbreeds). Later on he breaks into Bruce Abbot's house, Yosef attacks Sara and tries to impregnate her. Abbot sprays hydrochloric gas over the lab, killing Yosef, but he is killed by the latter.
- He shares the same eye color with Amelia in his alien form.
- He attempted to impregnate Sara in the same way that Patrick impregnated Eve.