Hylian Loach

The Hylian Loach is an extremly rare fish and notoriously dificult to catch fish in both The Legend of Zelda: Ocarina of Time and The Legend of Zelda: Twilight Princess.

Twilight Princess
In Twilight Princess, loaches can be caught at Hena's Fishing Hole. The only way to catch them is to either aquire a Frog Lure or a Sinker Lure. In Hena's childhood, her favorite book was Hylian Loach: Twilight Fish. She had completly memorized it by Twilight Princess.