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.
The frozen wastes stretch for miles around. Something waddles through the snow. It's a penguin: An emperor penguin. It waddles slowly, meandering toward the sea. The ranger freezes. "Stay very still," he warns. "Don't move at all." "What is it?" I ask, breathlessly. "It's the most dangerous creature in the whole Yahoo Tundra, and that penguin's about to kick its butt..." (Sorry, Epi! I couldn't resist!)