Brenna was the second mermaid to appear on the show. She has a short temper, but is a really nice girl. She becomes a mermaid by following Amy to The Secret Cave, though she did not know it was Amy at the time. Her friends are Amy, Kelsey and Blaire. She also loves a little spikey ball, that she drew a face on and named bill. She has two sisters seen on the show, Gracie and Lilly (Lilly knows about her being a mermaid).