Someone who is boring with a dry sense of humor. They are often quiet and/or business-like. It is difficult to make them laugh with a joke of good humor, but on the rare occasion they do laugh, it is over something not that funny.
The "Lifeless Hull" portion comes from the fact they have very little personality, and almost seem empty inside, much like a hull.
Shelly: "Yeah, I know. I'm beginning to question if he has a soul."