In the Dreamtime a man called Djanggawul, guided by the Morning Star, set out in a canoe with his two women (the trio is collectively called the Djan'kawu) and his pet goanna Djanda to cross the sea from Bralgu, the mystical Island of Spirits, to the shores of north eastern Arnhem Land. They intended to teach law and ceremony to any dhuwa people they might find living there, and to distribute totemic embems (rangga), and ceremonial armbands and headdresses made from cane tightly bound with bush string interwoven with red lorikeet feathers. All of these were wrapped up in a round pandanus mat in the bottom of the canoe together with dilly bags and digging sticks both long and short, with which they intended to plant trees, dig for yams, and thrust into hard ground to make fresh water drinking wells and also sacred waterholes to be used only by old initiated men. The longer sticks were for use by Djanggawul, and were called mauwulan (penis) and the shorter ones ganinjari (yam), used by the women, resembled sharp-pointed long yams.
After the trio had worked for a long time among tribal groups living in northeastern Arnhem Land, they crossed over the Arafura Sea in a bark canoe to Elcho Island. Here Djanggawul left sacred deposits of red ochre with which the men were to paint their bodies for ceremonies, while the two women thrust their yam sticks into hard ground in a number of places to make waterholes. They then proceeded to show the women how to dig for yams, using the sharply pointed end of their digging sticks. The trio made a bush shelter at a place called Bararabu, and lived among the people for many months. Djanggawul continued to instruct the men in law and ceremony, while his two wives taught Aboriginal women how to obtain food from the land and the sea, the art of making dilly bags for carrying yams, wild honey and other foods, and how to make waterproof vessels from paperbark.
One day all of the women were sitting beside their camp fires cooking yams when they noticed mangrove worms (wurrkadi) wriggling out from holes in the mangrove roots and coming towards some of the yams which the women had lifted out of the fire. They ate so much that many of the witchetty grubs became ill and died. The two sisters showed the Aborigines how to dig the witchetty grubs out of the roots and eat them raw. They soon became a favourite food and a great source of protein for all the people, and were made sacred to the Galpu tribe as one of their totems or "dreamings". The Galpu people were not allowed to eat the worms. Djanggawul also made stingray another of their totems when he saw swarms of these marine creatures coming in each night to feed among the mangrove roots.
In this painting the artists have depicted mangrove worms and stingrays. White crosshatching represents the spittle of the worms. Because they ate too much yam flesh they became sick and tried to eject it from their mouths by spitting. The dots (birrtji gunirr) along the straight lines represent hills and edible clay. The black circles represent the bodies of old dead mangrove grubs and also coals from the fires where the Aborigines were sitting around eating yams. The dots around these black circles represent young grubs.