Together with his friends Pig, Duck and Hare, Frog lives in an anthropomorphic animal world.
He observes daily events from a childlike perspective, offering children insight into social interactions.
Frog and his friends enjoy life and deal with real life issues, such as fear, love, sadness, and loss, making these difficult subjects and emotions more understandable for children.
Velthuijs received the prestigious Hans Christian Andersen Medal in 2004 for the illustrations of his own Frog books.
When Max Velthuijs died in January 2005, Carmen Diana Dearden said: ‘like in Frog and the Birdsong, “all his life he sang beautifully for us,” and he will always sing his lovely songs through his books.’ [2]