Zeder, (noun): a small, sleen-like, carnivorous mammal which inhabits the rainforests inland of Schendi, esp. along the Ua River; grows to about two feet and weighs 8-10 lbs; is diurnal, can swim very well, and builds a stick-and-mud nest in the branches of a tree, where it spends the night.
There is however, a sleen-like animal, though much smaller, about two feet in length, and some eight to ten pounds in weight, the zeder, which frequents the Ua and her tributaries. It knifes through the water by day and at night, returns to its nest, built of sticks and mud in the branches of a tree overlooking the water.
Book 13: Explorers of Gor, Page 312