Update: I started this with 10 simple riddles from an old video game, and I'm running out of steam to finish it. Any suggestions? I will give contribution credit to anyone who significantly helps. If you don't want to post the answer to your riddle in the open, you can send me a PM, and I will post it the same way I did the others. Go to Comment
Mega thanks to Moonlake for finding a link to a ton of inspiring riddles. The first 10 are from Warlords Battlecry 2. The last 13 are inspired and modified from the link Moonlake found.
These riddles are not intended to be complicated. My players like coming across the occasional riddle-spewer, but they don't like waiting when the riddles are so hard that only one person could possibly figure it out. Go to Comment
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.