Henry and the Yeti by Russell Ayto
Henry is sure yetis do exist, and he sets off on an expedition to find one. He has packed everything he needs, including a camera to take photos for evidence. But can he find a yeti? And will anyone believe him when he returns home? A funny story about believing in yourself (and yetis) from a bestselling illustrator who has turned author too. (Titles include The Witch's Children and Captain Flinn and the Pirate Dinosaurs.) Children will love the twist ending in particular.