Leanan Sídhe
The Leannán Sídhe ('fairy lover') is a female fairy of the Aos Sí who takes a human lover, granting poetic inspiration but draining their life force so they die young. W. B. Yeats popularized her as a vampiric muse: 'The Gaelic poets die young, for she is restless.' Earlier sources (Lady Wilde, 1887) describe her as a fairy mistress who becomes a slave if refused.