A cartoon character with a sad expression trying to bite its own belly button, symbolizing the impossibility of the action. The character's facial expression and body language should convey regret and realization. The scene should be light-hearted and playful, with exaggerated features to emphasize the comical nature of the phrase '噬脐莫及'. The character should have a cute and whimsical design to appeal to young learners, making the concept of regret easy to understand.
