The World of Eric Carle The Very Hungry Caterpillar Happy convertible 3 in 1 high chair is the only chair your baby will need. Based on the popular children's book The Very Hungry Caterpillar, your little one will explore this wonderfully designed chair during meal time. Our ultra lightweight highchair converts between 3 stages: 1. highchair, 2. booster seat, and 3. youth chair that fits your little one at different ages. High Chair can fit child at 6m to 3 years; youth chair can fit child at 3 years to 6 years. The versatility keeps your child safe and secure during feeding time.