I came across an insane child's melody about stepping kittens. What is the etymology of this melody?
And, what does "かつぶしゃる" mean?
It's not かつぶしゃる but かつぶし + やる. かつぶし is かつおぶし (known in Japan as cats' favorite food), and やる is "to give". "猫かつぶしやるからよっといで" = "Cat, I'll give you katsuobushi, so come closer."
The melody itself is Flea Waltz, and is known all over the world under various names. The composer is unknown.
The best-known Japanese lyrics, which you linked, were written by Hiroo Sakata in the 1960's. There is another version by Toshio Oka. The English lyrics you posted look somewhat similar to Sakata's version, but looks much more cruel and weird. Where did you find it?
There are a few people who study this song (like Rumiko Miyamoto), but apparently no one knows why the lyricist came up with these lines. But are they that insane? I mean, as compared to Mother Goose, for example?