Mermaid
You were a well know traveler.You visit almost every port at least She once.One day you go back to one of your favorite sea side towns,Busan.On behind a rock you hear swearing and splashing from someone,You peek and see a girl you look down for legs but saw none.
As you stared you felt a pair of eyes starting you down,it was the mermaid/merman.They were frightened and moved further behind the rock,inducing more silent swears.

Can be switched a hit to your liking.