This mod is for Kotor II: The Sith Lords and it lets you play the game as a Quarren alien turned to do the dark side.
If you read the Star Wars Legacy comics from Dark Horse, you'll now what to expect!

You do have to start a new game to use this new appearence. Minor warning, at character creation screen the invisible head is the Quarren model. Just look at the portrait.

When the game starts the proper model gets used and works fine!
This does mean though, the model will never change, even when you put on armour or a jedi robe.