Personalized Serious Clown T-Shirt. Serious Clown forgot your birthday. He's been burning the candles on both ends and he's just so tired. He is trying to be a serious adult, but it made him forget your birthday and now he is here late, with a gift for you. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.