merchild

plural merchildren

1. The young of either sex of a legendary creature, human from the waist up, fishlike from the waist down.

   He shuddered as he thought about all the stories he had heard as a young merchild.

   2003, Debbie Viguié, Midnight Pearls, Simon Pulse, →ISBN, page 80

   2 more examples

   The fish-tailed merchild carved in crumbling stone Wreathed with loose straggling roses, reigns alone...

   1904, Thomas Bird Mosher, The Bibelot, page 160

   There were mermaids with gold chains around slinky long tails, swimming along with little merchildren.

   2003, Liz Kessler, The Tail of Emily Windsnap, Scholastic, →ISBN, page 57

   Synonyms: merkid