Tegaki

Tegaki, (手鉤 lit. "back of the hand hooks"), were a kind of kakushi buki (隠し武器; lit. "hidden weapon") deployed by the ninja of Japan.

Tegaki are claws use to climb up sheer wall surfaces such as brick, stone, concrete, and wood. They first appeared in the episode Rise Of The Turtles. They were fabricated by Donatello, they're sturdy and strong, but are not designed to hold up as weapons.

Official Description
Tegaki Also known as shuko, these claws are meant for climbing, not combat.