The brief was for an illustration of a different animal for each of the 6 levels in the Primary English range of books. Macmillan told me what animals they wanted, and the dominant colour scheme for each level. Though it was intended to appeal to younger children, we agreed that the animals should be drawn fairly realistically. In the end the client pushed for big googly eyes, which I thought wasn’t really necessary. But you can’t win every battle.
The illustrations were created in Adobe Illustrator, using a lot graduated colour and feathering for the tones, and with a bold outline giving a strong silhouette to the character.