Personalized Smart Biological Engineer Toddler Hoodie. Biological engineering, the profession for intelligent people text with the letter E in the engineering wearing a hard hat is a funny design with attitude for engineers and college students at back to school, birthdays, holidays and graduation. The Toddler Pullover Fleece Hoodie keeps little ones cozy and comfortable through all their adventures. Made with soft fleece and a smooth jersey-lined hood, it’s perfect for layering on chilly days. Ribbed cuffs and waistband help hold in warmth while side seam pockets add a touch of practicality for busy toddlers on the go.