The forest of HalÃ«fas is a strange place indeed. It has long been inhabited by the forest elves, a race of elves descended from the high elves that have lived for over 9000 years isolated there. This wood is patroled by a groupe of expert rangers who know the forest well, Tred lightly and unthreateningly here for you may find your end in Hathil’S arrow.
If a creature is transformed into another creature (say, a human into a dog), then that creature will become more and more accustomed to the new form until a point is reached where reversing the spell is impossible. A second transformation is possible, but the creature will have to go through the whole process again.