Moby Duck is a sea captain who was a friend of Donald Duck and Scrooge McDuck. He mostly appeared in the late sixties and early seventies. He first met Donald when his water mattress drifted out to sea. Donald was briefly Moby's first mate but he was later replaced by Dimwitty. Moby also had a pet porpose named Porpy. Moby briefly appeared in the story Dangerous Currency as one of the citizens who fought back the slime.