Smoothie bar takeover with mystery ingredient challenge

About this idea

Your elf has set up an elaborate DIY smoothie bar with labeled ingredient cups (spinach, berries, protein powder, etc.) BUT one cup is labeled 'Mystery Ingredient - DO YOU DARE?' filled with something unexpected like pickle juice, hot sauce, or sardine water. Include a challenge note: 'I triple-dog dare you to make a smoothie with the mystery ingredient and post a taste-test video!' Perfect for social-media-loving tweens who enjoy challenges.