These are the books by Odo Hirsch that are reviewed on this site:
Hazel Green, born leader, organizes a float for the carnival, with curiosity, flair, indignation, humour, intelligence and sensitivity (among other qualities).
Something's Fishy, Hazel Green
Two lobsters are stolen, but it takes a girl like Hazel Green and her friend the Yak to discover the truth of this mystery!
Yoss leaves his remote mountain village and goes off in search of adventure in the world outside. But he has a lot to learn about human nature.