When the Good Lord N’gai made his plans for all the creatures upon his earth, he made the hippopotamus as an animal of the forests and plains.
However, the hippopotamus was greedy and, finding plenty of food all round him and no enemies to worry about, he grew fatter, and fatter and fatter. The fatter he grew, the more he suffered from the heat of the Equatorial midday sun.
Day after day, when he waddled down to the river for his drink, he gazed with envy at the little fishes that swam in the pool which was cooled by the melted snows from far-away Mount Kenya. “Oh” he would sigh, “how wonderful it would be if I could live, like N’gai’s little fishes, in the clear, cool, refreshing water!”
The hippopotamus pondered over his trouble for many days, and eventually decided to approach The Lord of All Creation. “Please, Good Lord N’gai” he cried loudly to the heavens upon one particularly hot day, “allow me to leave the forests and the plains. Let me live instead in the clear, cool waters of your rivers and lakes, for the heat of the fiery sun is killing me!”
“No,” replied Lord N’gai, “for my little fishes are very dear to me, and if you were to live in the rivers and lakes, you might try a change of your eating habits, and begin to eat those little fishes. That would never do. No, you must continue to live upon the dry land.”
So the hippopotamus stayed sadly in his home in the forests and plains, where the sun continued to beat down mercilessly on his unprotected hide. “This is more that I can bear!” moaned the poor creature. “Please, please, Good Lord N’gai, let me leave the forests and plains, and become a creature of the rivers and lakes, I promise most faithfully that I will not eat your little fishes.”
The Great Lord N’gai thought the matter over, while he looked down upon the plains baking in the heat of the tropical sun, and eventually his heart softened. “Very well,” he agreed, “I will allow you to live in my rivers and lakes, but how will you prove to me that you are not eating my little fishes?”
“I will lie in the cool of the water by day, and at night I will browse along the banks of the rivers, and in the veils,” replied the hippopotamus. “I promise that I will not eat your little fishes.”
“But that will not be proof to me that you are keeping your promise!” pointed out The Great Lord N’gai.
“Well then,” answered the hippopotamus, “I will come out of the water every time that food passes through my body, and I will scatter my dung on the earth with my tail. All that I have eaten will be spread out in your sight, and you will see for yourself that there are no fish bones. Surely this will be proof enough!”
So to this very day, the hippopotamus comes out of the water to scatter its dung as it looks up to heaven and says, “Look N’gai, no fishes!” – and that is why hippos don’t eat fish!
(Folktale from the Kikuyu People – Kenya)