Idea 1: A Performance
The artist performs his act of moving inks/living canvas, sees the mermaid on centre of the circus in her large goldfish bowl performing, leaping through hoops and other water acrobatics. As crowd leaves artist meets up with her through the glass. The bowl is rather empty so he paints a fish onto the glass, which begins to move into her bowl and acts like a real fish. The two then encorporate this into a sort of double act and attract many people to the circus.
Idea 2: The Little Freak
Much like idea 1 the artist performs and soon the mermaid catches his eye. The mermaid is less enthusiastic about her water act/swimming and is far more interested in walking as she keeps on staring at the audiences' feet. The artist then proceeds after some design planning to tattoo her legs with ink, to create a design of legs on her large fish-like yet humanly morbid tail. As his tattoos come to life so does hers, obtaining legs. The two then either escape the circus or again make an alteration to her/their acts.