A sarcophagus. Like a
Chicago overcoat, but Ancient Egyptian. The most famous
Cairo Overcoat is used by the Homestuck character
Lord English; it is made of the fabric of spacetime and can transform from a sarcophagus into a real coat and back.
Stitch mutters to himself in his shop. He guesses Eggs and Biscuits are
roughhousing again, because the fabric of spacetime is tearing something fierce on
Lord English's CAIRO OVERCOAT. This sort of thing is exactly why he keeps a BACKUP COAT, and always leaves Stitch with one of them.
--Homestuck, Intermission 1