One Little Man Personalized Onesie. Choose from 6, 12, 18, or 24 month sizes. Celebrate the man of the house with our adorable Little Man Personalized Onesie! This handsome black onesie features a dapper blue tie to dress up your little businessman. To personalize, simply enter your child's name in the 1st Line of the Product Options, and we'll print it below the design on the onesie. If you're celebrating a first birthday with this Little Man Personalized Onesie, be sure to browse our fantastic selection of 1st Birthday Party Supplies for the perfect theme!