Hapshetsut gave the correct answer. The poisonous fish represented in many tomb reliefs is the fahaka; the puffer fish or Tetraodontidae. Its special defensive ability was to rise to the surface and fill itself up with air, so it couldn't be eaten. The hieroglyphic determinative that was its ancient Egyptian name, SPT, was also used phonetically as a verb, meaning "to be angry, discontent, puffed-up, to blow-up in anger".

These fish were so tough and their teeth so sharp, that even a dying one could bite off a man's finger. At Kom Ombos, it was taboo to kill or eat the SPT. Their migration was connected to the Nile's springtime inundation at Elephantine, "to the chapels of the fahaka."