Rare and mythical even in the Green Age, the Athasian unicorn survives today only in the foothills and Scrublands South of Kurn. Even the vast majority of herders and Kurns have never seen a "unicorn" in their lives, although they have all heard of them. Typically, travellers that cross paths with an Athasian unicorn are none the wiser, since the creature uses its abilities to conceal itself. However, once the unicorn has seen them, it is likely to keep an eye on their trail for a few days. If the travellers defile the unicorn's territory, or light campfires during dry summer months, the unicorn might choose to make an appearance.
This is a companion discussion topic for the original entry at http://www.athas.org/articles/athasian-unicorn