Alien appears only within the Area 51 level in Nevada, the Aliens are presumed to have been recovered from the captured UFO space craft in the hanger. None of the Aliens are encountered alive, and as such serve more as decorations to the level design and a predictable feature to the location.
Their appearance is likened to the Greys of UFO folklore and popular culture, and their presence in Area 51 is directly tied to the myths surrounding the facility. This being the case, they serve no greater purpose to the plot of the game and are never referenced.
They have large, round hairless heads. They feature very basic facial features: Nostrils, a small mouth, ears, a pointed chin and slanted black half-closed eyes. They are taller than a human. Only four are encountered. The first Alien is encountered in a dissection lab, where it appears that was being given a autopsy. This Alien features open wounds on its body. The second is preserved within a display case with the Orcas. The last two are within their space craft, quite possibly alive but in suspended animation.
Their space craft is larger on the inside than on the outside, a demonstration of their truly other-worldly technologies and capabilities. The interior is almost organic in texture and quite dark. The floor squelches under Lara's foot. Trekking through the rather featureless rooms leads to what appears to be the cockpit of the vessel. Here the remaining two Aliens are found inside the walls. The circular room features chairs and control panels that only the Aliens seem to be able to operate. Element 115 can be found in the centre of the craft, the power source.
- Various details in Area 51 are tied to elements of UFO folklore. The blocks that can be pushed labelled Mj12 in the High Security compound refer to Majestic-12, a supposed secret government organisation that handles UFO related material. This reference is easily overlooked.
- The first Alien to be found on the operating table refers to the infamous Alien Autopsy footage released in the 90s.
- Element 115 was mentioned to being the energy source for the Extra-terrestrial Flying Disc recovered at Area51 Site-4 by the questionable Bob Lazar.