A colossal, segmented worm, Ub'thar boasts a rough, chitinous hide in mottled shades of dark crimson and bruised purple. Its immense, cylindrical body tapers slightly at both ends, covered in overlapping, leathery plates that appear wet and slick, hinting at a slimy, viscous texture beneath. The surface is adorned with numerous sharp, bony protrusions and a multitude of small, writhing tendrils around a gaping maw lined with rows of jagged, translucent teeth, suggesting a firm, yet pliable form.