A Japanese word "Kokoopa" is a nearly equivalent term of Koopaling. But these words aren't the same at all. Because Japanese "Koopa" is the individual name of the king of turtles.
I surmise that the Koopa Kids were named by N.O.A. staffs. When SMB3 was put on the market in Japan, Koopalings didn't have any names. It was after SMW that each of Koopa kids were named. But the U.S. version manual of SMB3 is listed the koopa kids' names. When kids' names were known by SMW, I regarded them as strange. "Why aren't they named for Korean cuisine? Although they are the Koopa's kids." Koopa is the pronunciation in Japanese of Korean risotto gug-bab (literally : soup-rice). In the Japanese version, many characters have names appropriate for Japanese. However, Koopalings' names are not so. It is thought that the reason for their names being unrelated to Japanese is that the American named them.go back