Actually there animals with three eyes. Many lizards have a third eye called a parietal eye (or pineal eye). With this eye they cannot see 3D figures or images as we do with our eyes, but they do see shadows (changes in light/darkness). Have you ever noticed a lizard react to a large bird flying overhead by scurrying away? Did you notice the lizard never looked up, yet somehow he knew the bird was there? Of course, some do look up, but many don't ...they don't have to. That is because his parietal eye detected the shadow the bird cast as it crossed overhead. Iguanidae (lizards in the Iguana family) and Tuataras, and probably others, have this parietal eye.
Spiders, Scallops and the tuatara - New Zealand reptile - have more than one eye. Most reptile are said to have 3 eyes and insects tend to have more than two eyes.
Tuatara , it is a reptile. Also search for "parietal eye", also known as a parietal organ.
The tuatara has a third eye on the top of its head called the parietal eye.