The rake

A large hairless dog; a deformed, lurking human; a naked, hulking creature of unknown origin; no one can quite decide the true nature of The Rake, which might make it even more horrifying. The entity gets its name from the large claws it uses to decimate its victims in their sleep so, you know... don't read this story before bed.
http://www.creepypasta.org/creepypasta/the-rake