A large vertical cave has a constant, strong wind blowing out of it from the bowels of the earth. If one was to jump into the currents they would have a controlled ascent on the winds till they reached a height where their weight and the winds force reached equilibrium. Impossible to climb down naturally. What is it? Natural winds from the earth or a complex magical protection for an underground lair?
Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine.
Elven Light Horse - a lithe and small animal well suited to the forest home of the elves. It has semi-cloven hooves, a longer tail, like that common to unicorn illustrations, and always a snow white pelt. Lives inthe forest, able to stand on back legs to crop leaves from the lower branches of trees. Shy and easily frightened, but at peace when around elves.