(St.). According to tradition, St. Patrick cleared
Ireland of its vermin; one old serpent resisted him; but St. Patrick
overcame it by cunning. He made a box, and invited the serpent to enter
it. The serpent objected, saying it was too small; but St. Patrick
insisted it was quite large enough to be comfortable. After a long
contention, the serpent got in to prove it was too small, when St.
Patrick slammed down the lid, and threw the box into the sea. To
complete this wonderful tale, the legend says the waves of the sea are
made by the writhings of this serpent, and the noise of the sea is that
of the serpent imploring the saint to release it.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894