Humongous

A party of privileged teenagers are enjoying a day's boating on a beautiful lake when a sudden pall of dense fog immerses them in a nightmare of unspeakable horror... They run aground on Dog Island, which owes it's name to the pack of vicious hounds kept by the only inhabitants, an old woman and her son, whom no one has ever seen. Searching for shelter, they keep seeing the grisly remains of all kinds of furry animals. But worse sights are in store for them. For they have yet to meet the woman's son, and discover for themselves the reason she has kept him there...