Here's a quiz from a recent Riko match between "The Usual Suspects" and "Kansas City." You're on lead on the first board of the match and, without trying to do anything exotic or brilliant, you lead the Gremlin, the only card in your hand that allows them to make the contract.
The Gremlin looks like an ordinary card when it's in your hand, but it turns into a monster when it hits the table. Which one is it? Spot the Gremlin!