This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Lightning Bird (Southern Africa)
The impundulu (which translates as "lightning bird") takes the form of a black and white bird, the size of a person, which is said to summon thunder and lightning with its wings and talons. It is a vampiric creature associated with witchcraft, often the servant or familiar of a witch or witch doctor, which attacks the witch's enemies.
It is said to have an insatiable appetite for blood. Sometimes it takes the form of a beautiful young man who seduces women. Among certain African tribes the hammerkop is believed to be the lightning bird. Among others the lightning bird is believed to manifest itself only through lightning, except to women, to whom it reveals itself as a bird.