Husk

Husks appear in Ghost Light When Josiah Samuel Smith the alien survey sent to earth by another alien called Light changes form to mimic the dominant species he leaves behind Husks. There are two of these in the lower observatory of Gabriel Chase, one of these looks like a reptile and the other an insect. They are both wearing clothes similar to that of Josiah. There is a third Husk in the upper observatory that is very alike in appearance to Josiah but has a face covered in flaky dead skin. Husks are free to move around the two in the lower observatory attempt to capture Ace but Nimrod uses a lantern which they apparently afraid of, to fend them off. When Joisah is hurt he is carried upstairs where he leaves behind his old form ready to become a new one for the coming night, this act creates the Husk in the upper observatory. What end these Husks come to is not clear.

Behind the Scenes
According to the writer Husks were placed in the story because the first two episodes lacked monster and so they were added.