[2] Adults of the species grow to 50 cm in total length and can reach a weight of 500 g. They are predominantly black, but are liberally dotted with white.

Malpelo Island has few resources; the only available foods are crabs and seabirds, especially boobies.

[2] The species is endemic to Malpelo Island, a possession of Colombia, where it is common.

Similar to the marine iguana, it has the ability to swim for short distances, although this is not related to its feeding habits.

It shares the island with two other endemic lizard species, Anolis agassizi and Phyllodactylus transversalis.