I heard an amazing story set during WWII. A ship was torpedoed by the Nazis in the South Atlantic, and a group of men ended up clinging to debris, floating and waiting for rescue. In the darkness, they suddenly saw something black blotting out some of the stars right above them, and several of the men were grabbed by the tentacles of a giant squid.
I don't remeber if any of them were taken down into the sea by the suid, but at least one of the survivors had the tell-tale sucker marks on his skin after the incident.
OOPS! "Suid" = "squid", obviously. I'll try to post a link to the above story if I can find it.