Riddle Me This

Do you enjoy a good riddle? Or stumping others? For this swap you will get a chance to stump your partner. You will send one naked postcard. No homemade or ad cards, zazzle cards are okay. On the back write a riddle for them to solve. Do not include the answer. Newbies allowed. Will angel if necessary but flakers will be banned from all future swaps. No recent unexplained/unresolved ones or threes in last 6 months.