Personalized Superhero 1st Birthday Women's Plus Size V-Neck. Happy 1st birthday! Celebrate your baby's first b-day with this cute I'm 1 superhero design. Happy Birthday one-year-old! So comfortable you'll want one in every color! These versatile v-neck t-shirts are great to wear to the office or at a weekend BBQ with friends. Available in a wide range of colors to compliment any wardrobe, these shirts are softly shaped to complement a plus sized woman's curves.