Generate a 3D model of an egg-shaped artifact made of aged ivory, formed by tangled, interwoven rats. Their bodies compress into the ovular shape, with knotted tails reinforcing the structure. Hidden beneath them, centipedes lurk in gaps, each engraved with an identical ancient rune. The ivory appears cracked and worn, evoking a dark fantasy, occult relic. The design balances grotesque beauty with eerie elegance, as if it holds a forgotten purpose or concealed entity.