Barbary Terror

The Barbary Terror, also called the White Terror, was a supernatural being which appeared to sailors at sea and took their souls. Captain Benjamin Briggs dismissed it as "ungodly superstition". When a Dalek came on board the Mary Celeste, the crew and passengers mistook it for the Terror and jumped overboard to get away from it. (TV: The Chase)

Behind the scenes

 * In the novelisation, the sailors instead mistake the Daleks for "the folk of the sea", since the "Barbary Terror" actually refers to which had been suppressed decades earlier.