A manifestation of
death in the tales of
DC Comics The Flash second series of
comic books to bear that name. The
native americans called it
slow lightning. The original Flash
Jay Garrick had encountered it before, as did
Max Crandall. It had been spotted before the deaths of
Johnny Quick and
Barry Allen. It tried to take
Wally West but missed and took his fiance instead. Then it chased him down to
the end of time, where death no longer has meaning. West was able to cheat this manifestation of death and get his girl back, but they now know what's "waiting for us all at the end of the race."
It is believed this story is a paradox of the DC Universe because fans of The Sandman know that Death cannot be outran. She takes many forms and The Black Flash is probably one of them. At the end of time it is chronicled she's the last to go when the universe is through, so Wally would have had to run past the end of time to avoid her.. or him or whatever.
An alternative way for a speedster to go is by way of the Speed Force. Old speedsters never die; they just reach terminal velocity.