My little mermaid

Oh to be four years old again. Unencumbered by gender specific role play the four year old has become, in the last month or so, Spiderman, Superman, Mario, Sonic, Yoshi, Knuckles (think video games), little Barbie and a mermaid. His last incarnation is the mermaid, I believe, brought on by his swimming lessons. Occasionally one of the family will prompt him, asking if he is really a merman or Spongebob character Mermaid Man, but no, he insists he is just a mermaid. He also insists that I make him a mermaid costume. In an effort to stall his persistent demands I asked him to do a sketch for me of what he wanted.

Seems simple enough, although, I'm not sure where I will get the curly hair.