yes because if you felt a frog you could feel a hard bone on its back Yes. Horned Lizards (Toads) have backbones. This makes them vertebrae. Yes. Horned Lizards (Toads) have backbones, making them vertebrae animals.
They drink water. If you want to keep a horned toad, then put a water dish in it's habitat not to deep that it will drown in and also make it in ground so it's easier for the toad to get in. Horned lizards (toads) drink water.
Horned Toads are a fairly common species, with the Texas Horned Lizards being protected, but still incredibly common. It's impossible to estimate how many are left without consulting someone in a higher field.
Horned Toads are cold-blooded animals. This means that their blood is heated by the sun, not by their own bodies. They have to sit in the sun to stay warm. Their bodies don't overheat as easily as ours, mammals, do.
Yes. They have several, including snakes, birds, coyotes, cats and dogs. Snakes, birds, coyotes, cats, and dogs all prey on horned toads, which is why they have developed so many extraordinary defenses.