Though Spider-Woman is hardly the worst character to debut during the chaos of the early Bronze Age of Comics, her initial origin is certainly one of the least prepossessing.
Most Marvel fans know that Spider-Woman was born from an attempted trademark violation. Sometime in 1976, the year after Modred the Mystic made his two appearances, Filmation Animation Studios contemplated a new set of superheroes for Saturday morning television. One of those superheroes was going to be named Spider-Woman. Marvel Comics, who held the trademark on Spider-Man, may have made some legal protest to Filmation. The upshot of the conflict seems to have been that in order for the company to claim "Spider-Woman" as a Marvel trademark, the company needed to publish a Spider-Woman. Thus, in MARVEL SPOTLIGHT #32-- dated February 1977 and thus actually issued in late 1976-- a Spider-Woman was introduced. Presumably Marvel so informed Filmation, for when the studio debuted its cartoon lineup in late 1978, their arachnid-character had assumed the new name "Web Woman." The lineup failed so quickly that had Filmation done their own Spider-femme, few would have remembered her.
The debut of Marvel's heroine was not much better. Archie Goodwin cobbled together a loose story in which an amnesiac woman named "Arachne" was captured somewhere in Europe when agents of the organization Hydra observed that she had strange powers. Hydra's leader Count Vermis formulated a plan to turn Arachne into an assassin to kill Hydra's foremost enemy, Nick Fury of SHIELD. Hydra apparently makes Arachne's costume for her and gives her the Spider-Woman name (though Arachne never uses that cognomen). Rather than taking time to devise some brainwashing device, the evildoers command a handsome blonde Hydra agent, one Jared, to make love to Arachne. Then the schemers arrange for Jared to be captured by SHIELD's European division while Nick Fury happens to be present.
Arachne attacks SHIELD, apparently willing to kill Fury even though Jared is still a living prisoner. Arachne herself accidentally wounds Jared fatally, after which Fury reveals how Hydra tricked the heroine, and Jared dies expressing revulsion for having even touched his super-pawn. Arachne then speeds to Hydra's base and decimates it, chasing down Vermis. The master villain then reveals that he knows that Arachne was the creation of the mad scientist The High Evolutionary, who mutated animals to become the demi-human Knights of Wundagore. Arachne was ostracized by the other creatures there, and thanks to Vermis' prodding, she breaks through her memory blocks and remembers that the reason for her outsider status was her heritage of being a mutated spider, given a human body.
Perhaps Arachne would have retained that status had she never been revived. But for whatever reasons, those of good SPOTLIGHT sales or of long-term trademark protection, Marvel decided to launch Spider-Woman in her own title. However, to give her some early exposure, the heroine became entangled in a very messy five-issue arc by Marv Wolfman in MARVEL TWO-IN-ONE #29-33 (July-November 1977).
Though the spider-femme's origin is only incidentally touched upon, the sequence does end with the revelation that she's actually a human mutated by exposure to a spider-serum, which story would be expanded upon in the series proper. It isn't necessary to go over every beat of Wolfman's five-part story. It's only relevant that Spider-Woman is recaptured by Hydra, that she becomes part of a whole world-conquering scheme, and that, though it's revealed that she's not repugnant because she's a reborn spider, Wolfman loosely repurposes Goodwin's idea that she somehow repulses people for an unknown reason.
The only other interesting point is that all five issues are confined to England-- and I theorize that Wolfman chose that setting so that he could revive Modred the Mystic, in whose creation Wolfman was loosely implicated. True, one of the other guest-stars who teams with the series-star The Thing is also Shang Chi Master of Kung Fu, and his character was based in England. But Shang Chi vanishes from the sequence after issue #29, while other, more important aspects of the story evolve from the release of four elemental demons who are trying to capture Modred, who's still a resident of Old Blighty. At the story's conclusion, Modred is actually the individual who divines that Spider-Woman is a human being. Wolfman would later seek to explicate this facet of the character's nature in the first eight issues of SPIDER-WOMAN.
I don't know if Wolfman cherished some hope that Modred would accrue some strong repute from the story. But what happened was that roughly two years later, Roger Stern made Modred one of the puzzle-pieces of the aforementioned AVENGERS arc, "The Yesterday Quest"-- and for the most part, Modred did not come off looking good in said arc and the character remained a minor figure for several years after.
As for Spider-Woman, neither her SPOTLIGHT debut nor her TWO-IN-ONE appearances cast her in a very strong light. Yet as Modred declined, she advanced-- and the early issues of her own title show that she had more staying-power than the trademark-swipe that led to her creation.
