The fairy shoemaker. (Irish leith-bhrogan, from leith-brog, one-shoe maker, so called because he is always seen working at a single shoe.)
Do you not catch the tiny clamour, Busy click of an elfin hammer. Voice of the Lepracaun singing shrill, As he merrily plies his trade?
W. B. Yeats: Fairy and Folk Tales, p. 82.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894