And you did it superbly .
I googled monster movie with deformed joints. Only found this
http://www.imdb.com/title/tt0129852/
and mmovieforums threads.
And this
http://www.imdb.com/title/tt0365513/
nd hilariously, one for cat sidhe
https://books.google.com.au/books?id...joints&f=false