Aska kunai

A kunai is a Japanese multi-tool, often depicted as a handheld or thrown dagger. Traditionally, only the tip is sharpened, while the sides are dull; in most fiction and modern reproductions, however, the blade is sharp all the way around.

The kunai is very much ingrained in tales of ninja and its ubiquitousness is synonymous with the shuriken. As a prominent work of fiction involving ninja, Teenage Mutant Ninja Turtles have a number of characters that utilize the weapon.

Prominent users