3D animated video: A cute chibi baby (curly orange hair, red-yellow mail-themed outfit) rides a playful brown pony on a colorful urban path (mail truck, red mailbox, vibrant street backdrop). The pony starts with slow, gentle steps—its hooves tap softly on the path (making tiny mail-envelope sparkles drift), and the scene glows brighter with sunlight. It then accelerates into a lively dash (trotting quickly forward along the street): its body blurs with motion to highlight speed, the soft fur shimmers dynamically, and faint mail-themed particles scatter in its trail. As it moves, the pony continuously blows a steady stream of envelope-shaped bubbles (glowing with street light) that drift upward, wobbling gently with the breeze, before popping softly (releasing tiny cheerful-themed glitter). The baby holds the pony’s reins steadily, outfit fluttering slightly, feet dangling above the path, and a bright smile as they dash through the cheerful urban scene. Animation style: vibrant, playful, hyper-dynamic—add motion blur to the pony and floating bubbles; bubbles sync with the dash rhythm. 12-second clip, 4K, 60fps (ultra-smooth, urban-mail dash with whimsical, lively interactions).