Scarcey

Put simply, 'Scarcey' is a term given to an individual that favors sleep, rest and solitude over socializing. A Scarcey can be related to a loner, or more closely, a hermit, but the main difference between them is that a Scarcey likes to project the image that he interacts with people more often than he does. A Scarcey will most likely venture out with his chosen friendship group once every few weeks, to fool them into believing he still contributes to the group.
the word originates from the idea that every group has a friend that is very scarce in social occasions.