The original “man in the yellow suit” was Eobard Thawne, who became Professor Zoom, the Reverse-Flash. Thawne was a man from the future who got himself some super speed and a snazzy suit (don't ask how, just go with it) and became obsessed with Barry Allen and came back in time to bedevil him.

Who is the yellow flash that killed Barry's mom?

Nora Allen (née Thompson; 1959 – March 18, 2000) was the mother of Barry Allen, the wife of the late Henry Allen, and a good friend of Joe West. She was fatally stabbed by Eobard Thawne/Reverse-Flash and her murder was pinned on Henry who was subsequently sent to prison.

Who is the yellow speedster?

For the scientist whose identity he stole, see Harrison Wells (Earth-1). Professor Eobard Thawne (born c. 2151), also known as the Reverse-Flash, is a meta-human speedster from the twenty-second century, a descendant of the late Eddie Thawne, a time criminal, and the archenemy of Barry Allen/The Flash.