Here are three fish ornaments with hanging points. They come from plaques made three dimensional with openSCAD's mirror command. See thing:72403 Two Fish Plaques and thing:679428 Hexagonal antiprism bowls.

The ornaments need support for printing. A small flat surface has been created on each ornament which can be used as a placement aid. Fish_1 and fish_2 have a flat surface at the back of the tail while fish_3 has a flat surface on the bottom.