Shirahoshi

Princess Shirahoshi, known as the "Mermaid Princess," is a giant smelt-whiting mermaid and the youngest of King Neptune's children. She was first mentioned by Pappug, who claimed he knew her and promised to introduce her to the Straw Hat Pirates when they arrived at Fishman Island, although this was later revealed to be a lie. Shirahoshi appears in the anime "One Piece," which premiered in 1999.