Shades of
The Island of Dr. Moreau!
If you don't remember the 1896 story by H.G. Wells, here is an excerpt about the Beast Folk:
http://www.bartleby.com/1001/15.html#8
There was also a movie,
Island of Lost Souls (1933) based on the story,
and some other later movie versions with different titles.
http://www.metamovie.de/film/island.html