Alrinach (or sometimes Aldinach) is the demon who causes shipwrecks and is generally held to preside over floods, earthquakes, rain, hail and all forms of inclement weather. When visible, Alrinach is in female form.
For some unknown reason, during the middle of the 13th century the Raven King fell out with Alrinach. This seems strangely imprudent. One would expect that, like a careful king, he would wish to remain on friendly terms with all powerful supernatural beings - and a demon makes a shrewd enemy.