Our planet’s only sea-going lizard looks somewhat like a small Godzilla. The marine iguana (Amblyrhynchus cristatus) is endemic to the Galápagos Islands, and can be seen in this footage as it grazes underwater, captured by Steve Winkworth at Cabo Marshall. From National Geographic:
They look fierce, but are actually gentle herbivores, surviving exclusively on underwater algae and seaweed. Their short, blunt snouts and small, razor-sharp teeth help them scrape the algae off rocks, and their laterally flattened tails let them move crocodile-like through the water. Their claws are long and sharp for clinging to rocks on shore or underwater in heavy currents. They have dark gray coloring to better absorb sunlight after their forays into the frigid Galápagos waters. And they even have special glands that clean their blood of extra salt, which they ingest while feeding.
Their population is not well known, but estimates are in the hundreds of thousands. They are under constant pressure from non-native predators like rats, feral cats, and dogs, who feed on their eggs and young. They are protected throughout the archipelago and are considered vulnerable to extinction.
Related reading: The marine iguana’s evolutionary history.