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 characters are wandering through the bustling crowds of Lasopolis. A street conjuror is performing a simple summoning spell, something for the kiddies. A bit of odious purple powder in the fire, an incantation and out pops a saak-lizard or a muhmentarsh, writhing from the flaming brazier. But the conjuror has only a poor grasp of the arcane magical tongue. A few stuttered syllables could lead to Other Things coming through the brazier and giving the crowd more entertainment than they had paid for...