Whirlweasel

is a Rank A Wind-attribute Classic Yo-kai of the Charming tribe.

The Yo-kai Medallium bio reads; "It appears within a whirlwind, slicing through with a large scythe! Those who are slashed don't even realize it, as it moves as the speed of sound."

In Yo-kai Watch 3, Kamaitachi is one of the Yo-kai required to unlock Dandoodle.

Origin
Kamaitachi is based on the youkai of the same name (鎌鼬), meaning "sickle weasel". The kamaitachi is a weasel youkai with bristling fur, a call similar to a dog's bark, and most importantly steel-hard, extremely sharp claws shaped like sickles. The inhabit the Japanese inland mountain ranges (most notably Yamanashi, Nagano and Niigata), riding the mountain winds with such speed they are invisible to the human eye. They attack humans by rushing them, slashing them with such skill that they don't feel any pain, until they look down and realize they are covered in blood. Another version of the story tells of a trio of kamaitachi working together: the first one knocks the victim down, the second one slashes them, and the third one applies a healing salve to numb the pain, all within a few instants.

In Japanese, this creature gives its name to the legendary "vacuum slash" phenomenon, and is theorized to be another of Toriyama Sekien's inventions, born from a corruption of kamae tachi ("swordsmanship stance").