This is a set of developmental drawing I did in order to find the right look of that character:
Ideas for the boy's outfit. We needed him to look more round, meaning 'bear like'. Many layers of clothes and baggy trousers were something we needed:
Figuring out children's face anatomy and features:
Face expressions on a design we liked more than others:
Also the boy's dad needed to be designed. It was slightly easier as we only took the bear's design from the beginning and made it entirely human. I don't know why it wasn't so easy with the boy himself!