Julia Donaldson, Axel Scheffler. Zog and the Flight Doctors

She is a princess and a connoisseur of potions, pills, and herbs. He is a knight of iodine and bandages and a deft chiropractor. And Zog carries them back and forth, like a faithful steed. Zog has a soft, smooth takeoff... and a hard landing. Migrating doctors can cure a mermaid, a lion, and a unicorn, but can they save a king from a mysterious illness?