History. The Jesus Fish symbol goes back to very early Christian times. I gather that it's from the Koine Greek word for "fish" and what they can be the initial letters of. The transliteration in "icthyos" and there was no "j" in those days, so it began "iesus christos". So a fish symbol was a sort of secret sign for early Christians. Poser You could do this with a Poser displacement map. and use the displacement map to control blender nodes for colour, reflection, etc. You can use the UV scale and offset settings to put a detailed bitmap in a small area of UV space.