Husk

As their name and appearance imply, Husks are unfortunate divers infested and taken over by a parasitic lifeform, still wearing their now useless diving suit.

In-game

As of version 0.3.2.0 of Barotrauma, Husks act as disruptive enemies, small enough to enter the submarine's corridors and attack players therein. They are easily recognizable by the small tentacle emerging from the broken visor of their suit.

However, Regalis has mentioned the husks could eventually take on a more subtle role as a non-human traitor with unusual abilities and the potential to pass off as humans.