Abomination

These creatures are the result of alien experiments on abducted humans. They are found on the board of Mothership Zeta. They appear to be a hybrid of a human and an alien, and they are hostile to anything that is not one of them, including aliens.

Possible Bug
When they are shot, they bleed red blood, like humans and most other Earthen creatures, but they lose their limbs, they bleed green blood, like aliens.

Appearances
The alien experiments appear only in the Mothership Zeta add-on for Fallout 3.