The Rival was the speedster arch-nemesis to Jay Garrick in the Golden Age. Professor Zoom was the first villain to call himself Reverse-Flash, a 25th Century scientist who fought Barry Allen in the Silver Age. His successor was Zoom, an enemy to Wally West who replicated super-speed by moving through time. Inertia was the evil counterpart to Bart Allen, also calling himself Kid Zoom. The New 52 reboot introduces Daniel West, Iris West's brother, as the new Reverse-Flash, while Rebirth returns Thawne to the role.
The New 52