Grappling hook

Grappling Hooks and Grappling Guns are devices with multiple hooks (known as claws or flukes), attached to a rope; it is thrown, dropped, sunk, projected, or fastened directly by hand to where at least one hook may catch and hold. Generally, grappling hooks are used to temporarily secure one end of a rope. They may also be used to dredge for submerged objects. Historically, grappling hooks were used in naval warfare to catch ship rigging so that it could be boarded.

1987 TV series
The turtles have their own custom made grappling hooks shaped as turtles shells

2012 TV series
In the Nickelodeon cartoon the turtles have used grappling hooks as well as grappling guns, a scene from The Kraang Conspiracy where the turtles use their grappling guns to infiltrate the TCRI building was used in the third version of the series' opening sequence.

Playmates created a whole playset segment called Z-line Ninjas based on grappling hooks.