Dermasterias imbricata has a characteristic smooth, slimy feel and smells like garlic. It is mottled reddish-brown and orange with a greenish-grey perimeter and rusty brown gill areas. The madreporite stands out as a large yellow dot. The five arms are up to 15 cm long and the arm-to-disc ratio is from 2.4 to 2.9. Few if any calcareous plates show through the leathery skin. Along each arm are six to eight rows of squarish areas containing up to 22 papulae and 1 to 9 pedicellariae in each. The smooth shape of the marginals shows through the leathery skin especially in a dried specimen. Each adambulacral has a single blunt furrow spine tipped with a fleshy knob and on the oral surface, a ridge of tough skin parallel to the furrow and a flat oval spinelet. D. imbricata has four rows of tube feet.
Similar SpeciesDermasterias imbricata might be confused with Asterina miniata in general shape, but A. miniata is stiffer and feels like sandpaper.