Home » TerribleTwosOnesie   Terrible Two's Onesie.   Our adorable black onesie with "Terrible Two's" silk screen design is perfect for your 2 year old! 100% Cotton ~ Available in Size 18 and 24 months. Matching Headband available here. Onesie Size: Please Select...18 mo. (fits 22-26 pounds) Short Sleeve Onesie 24 mo. (fits 27-30 pounds) Short Sleeve Onesie 24 mo. (fits 27-30 pounds) Long Sleeve Onesie Price: $26.00