Charles Darwin, meanwhile, called them "imps of darkness"

By Alex Heigl
Updated April 14, 2016 04:11 PM

Marine iguanas are the world’s only underwater reptile, and footage of them is pretty rare, which is why everyone’s been pretty thrilled this week that close-up footage of one of them feeding has emerged.

Charles Darwin, who actually literally wrote the book on the Galapagos Islands (where Marine Iguanas call home), called them “imps of darkness,” while Captain James Colnett of the British Royal Navy wrote that “so disgusting is their appearance that no one on board could be prevailed on to take them as food.”

The little guys don’t help their own case so much: They actually sneeze big ol’ loads of salt-snot to help them purge excess salt they ingest while feeding, and they’re a mottled green-black, with large teeth, claws (which help them stay stable enough to feed in the ocean’s currents) and a spiny back. And they can grow up to four to five feet from tip to tail, which … well, that’s a big sea-lizard.

But despite all that, they’re vegetarians, feeding on algae and seaweed, and they’re quite in danger, primarily from feral cats, whose assaults on the iguana’s eggs and young have put a dent in the local population.