Claw thorn or foot thorn. The long thorn on the cock's foot is called claw thorn or foot thorn, which is a characteristic of cock. These thorns are sharp and curved behind the cock's toes. Claw thorns can be used for grasping the ground and defending, and can also play a role in marking territory to a certain extent. In the natural environment, roosters can be used to climb, grab food, protect themselves or fight with other roosters.