My apologies, I grew up with the 1957 Zorro TV show, which was a Disney product. I didn't know he existed before that; I thought Disney created him.

EDIT: Fun fact: when One Piece first came to America, Zoro was original renamed "Zolo." Because the American translators were afraid of starting beef with Disney over the Zoro/Zorro name.

Also, the Japanese language doesn't have any "L" characters in it; any words with an "L" get turned into a Japanese "R," sound, which is basically pronounced like a blend between an "L" and a "D."

So any Japanese words with an "R" in them could easily be translated as "L." Zolo and Zoro are pronounced the same to a Japanese person.