Since his debut in 1941, the Flash's storied career has been marked by struggles against a medley of villains. Some of them have acted as cannon fodder for the Scarlet Speedster to zip past by, but others have presented genuine threats to the Fastest Man Alive.
The likes of Reverse-Flash, Zoom and Gorilla Grodd have all gone up against various versions of the Flash and made their lives increasingly unbearable to deal with. Therefore, their notoriety in comics has grown to the point where they stand toe-to-toe with villainous greats such as The Joker and Darkseid.
But what about some of the Flash's relatively less impressive Rogues? The campier and less imposing villains often get a bad rep for their silly origins, motivations, and powers (remnants of the Silver Age of Comics).
However, recent years have seen these characters go from walking punchlines to intimidating foes who can put up a decent fight against the speedy hero.
From futuristic 'magicians' to shadow-based villains fuelled by darkness, the Flash's underdog villains have come a long way since their decidedly less threatening beginnings.
One of the more unsettling villains on this list, Murmur's MO is plucked straight out of a horror movie (or a particularly dark street-level comics storyline).
Dr. Michael Amar was once a renowned surgeon who turned to murder due to his untreated schizophrenia. His killing spree saw him cut out his victims' tongues in a twisted attempt to silence them and any voice he would come across. The wave of violence came to a close after Central City police officers Fred Chyre and Joe Jackham captured him and he was convicted due to his urge to confess, as well as evidence supplied from Barry Allen.
He was imprisoned in Iron Heights and sentenced to death, but his unique blood makeup made him immune to most toxins, including lethal injections. During his incarceration, he cut out his tongue and sewed his mouth shut.
Later on, he became a fully-fledged villain and committed heinous crimes such as killing inmates and guards in Iron Heights using a virus outbreak, attacking Metropolis alongside the Secret Society of Supervillains, and attacking police officers in Gotham City.