Personalized Coolest Nuclear Engineer Long Sleeve Creeper. The world's coolest nuclear engineer text and a snowman surrounded by a green glow and holding a Geiger counter is a funny design for engineers at birthdays and holidays. For chillier weather, dress baby in this soft long sleeve creeper in a great fitting 1x1 baby rib. 5.0 oz., 100% combed ringspun cotton, 1x1 baby rib. White is sewn with 100% cotton thread, Flatlock seams, Double-needle stitched rib binding on neck, shoulders, sleeves and leg openings,Reinforced three-snap closure on binding.