Sandslash can curl into a large ball, which allows it to roll to attack or escape, protect itself from heatstroke, and guard its belly. Sandslash is also adept at climbing trees and is prone to ambush its enemies from above.
Nidoran has barbs that secrete a powerful poison. They are thought to have developed as protection for this small-bodied Pokémon. When enraged, it releases a horrible toxin from its horn.