From Clogopedia, the Natural Selection 2 wiki
Lifeforms is the term given to the 5 distinct playable classes on the Alien team.
Skulk
- Main article: Skulk.
Gorge
- Main article: Gorge.
Lerk
- Main article: Lerk.
Fade
- Main article: Fade.
Onos
- Main article: Onos.