also, for a friendly NPC and an enemy type

The Elsens from off work as friendlies. They most likely came with the guardians to colonize where they are found (the most likely name for this colony would be New Damien). They look like this
[img=http://fc07.deviantart.net/fs70/f/2013/135/3/6/genderbent_elsens_by_barrychoppa-d65fjkc.png]
(female elsens are not in the original game, but they most likely do exist)
Elsens are devoted to their work, seem to have a species wide case of neurosis, panic at the sight of any danger, and speak with timid, shy voices. The also breathe smoke, and are known to raise a species of cattle that they use for both meat and for metal deposits.

When an elsen is put under exteme stress, or deprived of food or addictive drugs, they undergo a metamophosis that turns them into the feral, hostile burnts\
As seen here:
[img=http://fc06.deviantart.net/fs70/i/2013/127/4/7/off___dessert_by_petitecreme-d64glhl.png]