According to the Kayans and Kenyahs, head-hunting has been in vogue only for some eight to ten generations, certainly not earlier. Hose would put the time of its introduction to these tribes not more than two hundred years ago.
A Kenyah version of the origin of the custom is as follows; it was narrated by Aban Jau, a Sĕbop.
In olden days—and they still continue the practice—the Kenyahs took only the hair of a man killed on the war-path, and with this they decorated their shields.
One Rajah Tokong determined to retaliate on a neighbouring tribe that had killed some of his people, and having made all the customary preparations, he set out with his followers. They started, as is usually the case when going on the war-path, just after the padi had been planted, as this is a slack season, and paddled down the river and entered the jungle. On the third or fourth day, whilst they were cooking their rice on the bank of a small brook, they heard a frog croaking, “Wang kok kok tatak batok, Wang kok kok tatak batok” (tatak batok signifies “cut the neck,” in other words, “cut off the head”). Tokong listened to the frog and said, “What do you mean?” The frog replied, “You Kenyahs are dreadful fools; you go on the war-path and kill people, and only take their hair, which is of very little use, whilst if you were to take away the whole skull you would have everything that you required—a good harvest and no sickness, and but very little trouble of any kind. If you do not know how to take a head, I will show you.” Thus spoke the frog taunting them, and catching a little frog, he chopped off its head.
Tokong did not think much of this, but one of his bakis, or right-hand men, who was an elderly man, pondered long over the incident, and during the night he had a strange dream. He dreamt that he saw fields of padi, the plants being weighted down with their heavy grain, and in addition he saw an abundance of other food—sugar-cane, sweet potatoes, and what not. Next morning he said to Tokong, “I am very much concerned about what the frog said,” and then he narrated his dream. Tokong still appeared to think very little of it, but the other men strongly advised him, if they were successful, to bring back one or two of the heads.
Eventually they attacked the hostile house and killed seven people. The old bakis put three of the heads in his basket with the consent of Tokong, who had been persuaded that no harm could be done in trying this new venture. They returned at the usual breakneck pace, and found that they were able to travel at a great rate without much fatigue. On reaching the river they witnessed a phenomenon they had never seen before; the stream, although it was far above the reach of the tide, commenced running up immediately they got into their boats, and with very little exertion in the way of poling they quickly reached their farms.
To their surprise they saw the padi had grown knee-deep, and whilst walking through the fields it continued to grow rapidly, and ultimately burst into ear.
The usual war-whoops were shouted as they neared their home, and were answered by a din of gongs from the house. The people, one and all, came out to welcome them, the lame commenced dancing, and those who had been sick for years were sufficiently energetic to go and fetch water, and everybody appeared to be in perfect health.
The heads were hung up and a fire lighted underneath to warm them, and everything was very jolly.