Black KnightThe origin of the Black Knight legend is often "retrospectively dated" back to natural extraterrestrial repeating sources supposedly heard during the 1899 radio experiments of Nikola Tesla. The Black Knight satellite theory claims that there is a spacecraft in near-polar orbit of the Earth that is of extraterrestrial origin.
LeviathanIn the Zohar, the Leviathan is a metaphor for enlightenment. The Zohar remarks that the legend of the righteous eating the skin of the leviathan at the end of the days is not literal, and merely a metaphor for enlightenment.