One of the best developed talking otter characters ever. The otter people are in a side universe the protag visits, but it becomes one of the best she can access. And the otters and company are core to this story.
A black-furred female American Mink. Descended from mink that escaped from fur farms, Gru and her kind seek revenge against the humans, and so travel the countryside massacring wildlife and livestock alike. Taking up residence under a nearby pump-house, Gru sets about taking over the marshland. In anticipation of meeting Kine's resistance, Gru heads an attack on the Life Tree, murdering Kia and four of her kits. In the final assault on the pump-house by Kine and the weasels, Gru is thrown into the dyke and crushed by the pump.