Professor Eobard Thawne (commonly known as Professor Zoom) first appeared in The Flash #139 (September 1963). The archenemy of Barry Allen, he is the first supervillain to be called the Reverse-Flash.[6] While other speedsters cannot change the past without dramatic consequences, his ability to travel and manipulate time is able to drastically alter history and completely erase people from existence is due to having corrupted the Speed Force which created a negative version.