I have found the Book of Remembrances in the royal library… a wellspring of knowledge directly from the mouths of great rulers and scholars of the past… my only wish is that I might discover a way to add my own knowledge to this work.
T’Arkia, Imperial High Mage
In the middle of an unimportant combat with some bandits a burst of wild magic transforms all of the PCs and their opponents in to random animals and monsters. They retain their intelligence (though not, of course, the ability of speech). They can either carry on the combat in their new forms, panic, or otherwise react how they see best. After about an hour, they return, unharmed, to their normal form.