A colossal, ancient snake skeleton ...

A colossal, ancient snake skeleton designed as a massive cinematic entrance structure, featuring an enormous serpent ribcage arcing upward and outward to form a walkable tunnel-like gateway large enough for players to pass through, with each rib bone thick, evenly spaced, and anatomically accurate to emphasize scale and realism; at the front rests the gigantic skull of the serpent, partially embedded in the ground or stone, with massive hollow eye sockets, a long curved jaw, and sharp fossilized fangs, all heavily detailed with cracked bone textures, erosion, and weathering to convey extreme age, as if the remains of a legendary leviathan that died centuries ago; the spine extends behind the entrance with huge vertebrae segments that snake naturally into the terrain or disappear beneath sa