"Its yellow body is adorned with a white-rimmed black circle, designed to look like an eye. A strike in the eyes is fatal to a fish, so predators tend to aim for the eyes of their prey. However, if the pattern were to be mistaken for an eye and attacked, it would not cause a fatal wound.
[An eye for expansion]
The young fish who normally inhabit warm waters can sometimes be carried to cool waters by sea currents. When winter comes and the temperature drops, these young fish don’t usually survive. Some do, however, and these fish become very significant. If the surviving fish breed in these waters, the area of habitation for their species will be expanded."
(The trivia of this creature is unlocked by feeding it.)