Marine iguana
The Galapagos are home to the only marine lizard on Earth. It likely evolved its marine lifestyle because of the sparsity of nutritious vegetation on land, opting instead for seaweed. Darwin was not a fan, when he first saw them he wrote: “The black Lava rocks on the beach are frequented by large (2-3 ft), disgusting clumsy Lizards. They are as black as the porous rocks over which they crawl & seek their prey from the Sea. I call them ‘imps of darkness'”. You'll spot marine iguanas all over the islands, sunbathing on the rocks, and you may even find one swimming along the water's surface when you're snorkelling. On land, look out for their sneezes, which they do frequently to expel salt from glands near their noses.