My daughter asked me a mermaid fish tail for her Lego Friends figures. I cut off the upper body of "doesntfearzeus" swimming mermaid and stabilized the figure in front with the 3D shell from sysmes. Without this, it always fell over.
I printed the model with raft, but they might not needed.
Update 29.04.2020: Resized to original Lego Friends size.
Lego_mermaid_v5.3mf | 1.2MB | |
Lego_mermaid_v5.stl | 3.5MB |