Create a 3D low poly Tyrannosaurus rex with bold, geometric shapes. The model should have a strong, muscular build with a large head, sharp teeth, and a short, thick tail. Use vibrant colors and simple, clean edges for a playful, cartoonish look. Keep the arms small and the legs robust, with a dynamic pose, as if it's ready to pounce. The design should be minimalistic yet recognizable, with a friendly, approachable expression suitable for games or animations.