Light-Up T-Rex Costume size 3T - treat bag not included. battery-operated LED lights in the spikes on the head for a playful twist to their favorite dinosaur design. It’s crafted from a plush material with whimsical, colorful accents like embossed scales and shimmering foil fabric detail. Its plush material is soft to the touch and will keep your little T-Rex warm and ultra-cozy all day and night long. Lights up on the horned tail and is battery-operated (batteries are included).