Personalized 4th Birthday Train Outfit Baby Bodysuit. 4th Birthday Train Baby Bodysuit - Light Blue shirt for a boy has number 4 engine in red with colorful cars on this fun train themed party clothing or birthday photo tee. Our one piece baby bodysuit make great gift for newborns, babies, infants, baby showers and expectant moms. An ideal gift for any new parent who will want one in every color.