In Zoroastrian tradition the otter is a peculiarly sacred animal, the water-dog, a good creature of the pure element of water, and the Vendidad prescribes an enormous and famous penance for anyone who kills one, so highly was its life valued. Elsewhere the otter's evident playfulness, its sliding, its games, its sociability, gave it a gentler symbolism of joy, curiosity and the pleasure of the water, and coastal peoples wove it into their stories as a creature at home between land and stream. Bringer of a great curse in the North and a holy creature of water in the East, the otter carries meanings that range from tragic doom to sacred purity to simple play.
The otter appears occasionally as a heraldic charge in British coats of arms, generally granted to families or places whose name puns on the animal, such as Otterburn, and its heraldic meaning is generally given simply as vigilance or resourcefulness in the water, a comparatively minor and secular tradition beside the weight of doom and sanctity carried by the Norse and Zoroastrian otters recorded above. Otters remain a genuinely mixed conservation picture worldwide: of the thirteen living otter species, several, the sea otter among them, have recovered substantially under legal protection, while others, including some Asian small-clawed and smooth-coated populations, remain threatened by habitat loss and pollution, a modern layer of concern quite apart from the Vendidad's ancient penance for killing one.