Nilidon was an elven druid appearing in The World Tree, the fifth part of Heroes Chronicles. Tarnum the Immortal Hero was trying to find the World Tree, the source of all life, so that he could protect it from the mad god Vorr. Tarnum had found some secret caves in a remote mountain, and had come across some caverns full of trees, flowers and animals, and he guessed it was connected to the World Tree, but hadn't found the Tree itself. One day, the druid Nilidon arrived to aid him against Vorr. The rest of his army didn't trust the elf at first, as elves and barbarians have never been friends, but Tarnum greeted him warmly.