fantasy creature, Sydon, aquatic dragon, serpentine body, scales shimmering in ocean hues, long whiskers, webbed claws, majestic fins, swimming, underwater scene, coral reef, schools of colorful fish, sunken ship, treasure chest, dappled sunlight filtering through water, wide-angle shot, dynamic pose, detailed texture, high-resolution, vibrant colors, realistic, 3D effect, bubbles, marine life, epic, mythical atmosphere.