Animated voxel-art mammoth castle scene with an ice dragon

GOAL: Create a single self-contained HTML file using Three.js that renders a beautiful animated voxel-art 3D scene. MOTION: A giant woolly mammoth walks across a sea of clouds through a snowy night with the northern lights and a moon; the clouds drift backwards under its feet, and snow puffs up at every step. On its back, over a blue blanket with gold trim and leather straps, stands a stone frost fortress: walls with battlements, four round turrets with blue conical roofs and flags, two small houses with glowing windows and smoking chimneys, and a central keep with a big glowing ice crystal floating and slowly rotating above it. The mammoth has shaggy fur, a swaying trunk, long curved tusks and snow on its head. A crystalline ice dragon with horns, ice spikes along its back, glowing eyes and large wings rises from the clouds and circles the mammoth, leaving a trail of snowflakes, and breathes frost twice. Add soft shadows, voxel ambient occlusion, a snowstorm, drifting voxel clouds and a slow cinematic camera orbit. Make it as detailed and polished as possible.