 SPOILER: M. Night Shyamalan (qv) initially had a different concept  for the "Those We Do Not Speak Of" creatures. They were originally  conceived to be monsters similar to the rock drawings featured in  the movie trailers: similar to a Lion walking on its hind feet,  complete with shaggy mane. When the creatures were built to full  scale and brought on set, Shyamalan felt that the design was  completely unbelievable. The creatures were quickly redesigned, most  noticeably with the addition of the red cloak.