Among the different designs available, koi fish tattoos become more popular with men and women, probably because of its mystical symbolism. Koi fish is actually a type of goldfish that were bred specifically to have a wild and brilliant color scheme, with general symbolic meaning of luck. In Japanese folklore, the koi represents overcoming obstacles as told in a legend where koi swim along the Yellow river upstream will magically turn into a dragon. This is clearly an emphasis on overcoming adversity in life.