Who created Bitcoin Cash?
Bitcoin Cash is a continuation of the original idea of Bitcoin: a peer-to-peer electronic cash. Therefore it can be argued that Bitcoin Cash was invented by Satoshi Nakamoto. A better question is probably, “Who forked Bitcoin Cash from BTC?”.
The short answer is that the Bitcoin Cash hard fork was a collaboration among numerous individuals and development teams and its origins actually go back a few years before 2017.
For a detailed history of the origins of Bitcoin Cash, please read this reddit post by independent developer Jonathan Toomim.