Personalized 3rd Birthday Monkey Long Sleeve T-Shirt. he happy birthday monkey motif is a cheerful way to commemorate this special milestone in your child's life. Let your little wild one stand out with our unique and cute birthday accessories. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL