caribbean monk seals had a relatively large, long, robust body, and could grow to nearly in length and weighed . males were probably slightly larger than females, which is similar to mediterranean monk seals. like other monk seals, this species had a distinctive head and face. the head was rounded with an extended, broad muzzle. the face had relatively large, wide-spaced eyes, upward-opening nostrils, and fairly big whisker pads with long, light-colored, and smooth whiskers. when compared to the body, the animal's foreflippers were relatively short with little claws and the hindflippers were slender. their coloration was brownish and/or grayish, with the underside lighter than the dorsal area. adults were darker than the paler and more yellowish younger seals. caribbean monk seals were also known to have algae growing on their pelages, giving them a slightly greenish appearance, which is similar to hawaiian monk seals.