The Miles Warren clone version of Carrion first appeared in The Spectacular Spider-Man #25 and was created by Bill Mantlo, Jim Mooney, and Frank Springer.

[1] Carrion emerged as part of a storyline that was a sequel to the original Clone Saga and as a result he has one of the most complicated histories of any Spider-Man villain.

He decided he didn't want a second Spider-Man running around so Bill was asked to change the planned revelation of his extended story, even though the first chapter had already been published.

[2] The character's history has been retconned several times as successive writers changed the status of the various clones, the plans and motivations of Professor Miles Warren and other aspects from the stories.

William Allen first appeared in Spider-Man: Dead Man's Hand #1 (April 1997), created by Roger Stern and Dan Lawlis.

[7] Carrion sought to destroy Parker/Spider-Man several times before capturing Spider-Man and revealing to him that he was a decayed clone of Professor Miles Warren, also known as the Jackal.

Peter Parker searched Miles Warren's old lab and found a journal that seemingly answered many questions, though many years later the Evolutionary would cast further doubt on this.

Parker was followed by his university research student rival Malcolm McBride who discovered a test tube containing a strange substance.

When examining it, McBride discovered it was an advanced genetic creation that when exposed to air grew rapidly and consumed him, turning him into a second incarnation of Carrion, complete with all the knowledge and powers that the original had displayed.

[11] Initially, Carrion believed himself to be another clone of Warren but slowly found McBride's memories and personality trying to reassert itself.

[13] Later the mysterious Judas Traveller invaded Ravencroft and briefly transformed McBride back into Carrion during an encounter with Spider-Man.

Dr. William Allen ignored safety protocols and in the process was infected by a new, stronger version of the Carrion virus, transforming him into the third incarnation of the villain.

The latter now revealed that the original Carrion had indeed been a clone of Warren, created to incubate a virus to destroy mankind, but that it had been released too early and failed in its mission.

[19] A new version of Carrion, engineered by the Jackal, ran rampant through New York, jumping from one host body to the next (taking control of them in the interim).

[20] The Carrion virus joined the Jackal and a clone of Miles Warren in their battle against Superior Spider-Man and Scarlet Spider.

Spider-Man tries to appeal to Ben, but Jackal ignores him and takes over J. Jonah's broadcast to tell the world that they will all die and be reborn.

[25] The creature called Carrion is created when a genetic replicator virus derived from the mutated DNA of Professor Miles Warren comes into contact with a human being.