Possible Clues:

• Avian alarmist
• Bird who says 'The sky is falling!'
• *Doomsayer in a children's story
• Doomsayer of kiddie lit
• "The sky is falling!" critter
• Falling sky fearer
• Cautioner of calamity
• Mistaken cautioner
• Fairy tale alarmist
• Who thought the sky was falling?