For a little over a year during the mid-1970s, readers of The Defenders were introduced to an ongoing, head-scratching sub-plot involving a character which appeared to have nothing to do with the principal characters of the book, or, for that matter, anything or anyone else. Created by writer Steve Gerber and artist Sal Buscema, the Elf with a gun, as it came to be known, received a brief profile in the PPC eight years ago which dealt with its baffling modus operandi and mission; yet it seems negligent not to have also included each of his unfortunate victims, none of whom would appear to be relevant or of particular importance to any Marvel story except as unknowing, unsuspecting targets.
Four victims in all--the last of which didn't even merit a name, and, for what it's worth, the only one who even indirectly crosses paths with one of the Defenders.
I could find no direct quote in which Gerber expresses his thoughts on the whys and wherefores of his homicidal creation, though reportedly he remarked words to the effect of the Elf being "a backhanded metaphor for the chaotic and inexplicable nature of everyday existence," which, if accurate, begs the question of just what he had in mind for bringing this character to fruition in The Defenders. Of course, it all became moot following Gerber's departure, when, in 1977, the character was unceremoniously and summarily dealt out of the book by writers Roger Slifer and David Kraft (while, appropriately, being completely unrelated to the main story).
In a later series of stories, however (published well after Gerber had left the book), writer J.M. DeMatteis provided the diminutive assassin with a backstory that explained its actions and purpose as an agent of the mysterious group known as the Tribunal, whose goal was to pinpoint the cause of Earth's future destruction. Unfortunately for the Defenders, that would mean a few more casualties in the crosshairs of this Elf with a gun.
Yet it turns out that there were no casualties to speak of at all--only displacement, as a member of the Tribunal elaborates on during the group's confrontation of the core Defenders. Coincidentally or not, the issue in which we learn the answer to the mystery of the Elf is published seven years to the month after Gerber's last scripted appearance of the character.
We see that even the Tribunal can get its facts wrong, since it omits two people from its listing of "victims" while giving the name of another ("Richard Kessler") whom our Elf never paid a visit to.
A curious footnote to this story arrives nearly thirteen years later in 1996, when Gerber returns to Marvel for an assignment on Spider-Man Team-Up--a story that involves Peter Parker, Ben Reilly (as Spider-Man), Maynard Tiboldt (better known as the Ringmaster), the Circus of Crime... and an Elf with a gun, the nephew of the elf who was mowed down while getting a bead on our paper boy Greg.
This being the mid-1990s, Gerber's tale is as chaotic as Marvel itself was during those years, so I'll leave it to you to sift through the full story. You might as well know beforehand, though, that this new elf's story is left unresolved--which you'll probably agree is par for the course.