Ceasg

The ceasg is a Scottish Gaelic mermaid with the lower body of a grilse, a young salmon, also called maighdean na tuinne, the maid of the wave. The most famous local tradition is the Mermaid of Kessock: a man named Paterson caught her on the shore by the Kessock Ferry and removed scales from her tail to force her into human form, married her and had children, until a child found the hidden scales and she returned forever to the sea. If captured she grants three wishes, but her song can also lure men to drown.