Molting is a universal process all Xenomorphs go through. When a xenomorph molts, a block overlay is applied over their model signifying their process.

Not every xenomorph goes through the same stages of molting, some have more molting stages than others, and others less. However, you should usually suspect that they’ll have upwards of 4-5 on average.

What does molting do?

Molting signifies the “age” of a xenomorph. Overtime as a xenomorph molts more their HP increases but so does their size. Using this, players can tell when for example, a queen will be easier or harder to fight depending on their size as seen within the guide book.

What does it look like?

It appears as a thick, black overlay on a xenomorph. For example,

An Aberrant Drone in the process of molting.

Every xenomorph molts, including xenomorphs like the Empress or Queen.