Lake Champlain Monster: Commonly known as "Champ", a legendary monster said to inhabit Lake Champlain.
Lemuria: Legendary lost continent of the Indian Ocean, rumoured to be the original Garden of Eden.
Leprechaun: In Irish mythology, an elf-like creature around 1 metre tall.
Leviathan (1): A sea monster referred to in the Old Testament (Psalms 74:13-14; Job 41; Isaiah 27:1).
Leviathan (2): A political philosophy book by Thomas Hobbes, published in 1651. The full title is "Leviathan or the matter, forme and power of a common-wealth ecclesiasticall and civill".
Levitation: The raising of a body into the air without physical aid.
ley lines: Patterns and alignments of invisible energy said to connect various sacred locations, e.g. churches, stone circles, burial grounds, etc.
Loch Ness Monster: A legendary creature said to inhabit the Scottish lake, Loch Ness.
Lucifer: The name of Satan before his fall from Heaven.
lycanthropy: In folklore, the ability of a person to change into animal form. In psychiatry, the delusion of having been transformed into an animal.