One 1st Birthday Rebel Onesie. Choose from 12, 18, or 24 month sizes. Celebrate your little wild child's birthday with our super cute 1st Birthday Rebel Onesie! This baby blue onesie features angel wings and punky lettering that lets everyone know who'll steal your heart, and maybe some cookies, too. Browse our rad selection of 1st Birthday Rebel Party Supplies, from tableware to decorations, and make your little rocker's birthday extra special.