The skin of some terrestrial animals such as reptiles is protected by

• Reptiles have dry, scaly skin. The skin of reptiles is covered with scutes or scales which, along with many other characteristics, distinguish reptiles from animals of other classes. 
• Reptile scales are often brightly coloured and vary in shape and size throughout their body. These scales are mostly made of a hard substance called keratin.

So, the correct answer is 'Dry scales'.