Usborne The Book of Three

Taran dreams of fighting heroic battles instead of being an Assistant Pig-Keeper...until Hen Wen, the magical pig, disappears. With the land of Prydain under threat by the evil Horned King, and Taran searching for Hen Wen, he is drawn into a dangerous quest. Coming face-to-face with warriors and witches, a princess and a poet, creatures fierce and friendly, Taran is about to learn what it truly takes to be a hero.