This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Leanashe (Irish)
The leanashe is an ancient Irish mythical monster, a possession spirit or vampire. Variations of the word include Dearg-Du, Dearg-Dul and Leansídhe. In Ireland many druids speak of Dearg-Duls which has to be killed by building a cairn of stones upon the grave. The Dearg-Duls can't shape change.
Very little is known about the Dearg-Dul. Often considered the Irish version of Scottish version of female vampires and succubi, this Irish vampire can be held at bay by piling large amount of stones on its grave - but no Irish mythologist can find any reference to it. On the 'Isle of Man' it is a blood-sucking vampire and in Ireland the muse of poets.