Probably the weirdest thing about the upcoming Middle-earth: Shadow of War is that Shelob, who as I understand it is well-established in Tolkien's mythos as a monstrous, malevolent spider, is in fact a woman. More specifically, a leggy, raven-haired woman with a penchant for whispering in your ear, and who may or may not hold the key to bringing about Sauron's defeat. But Monolith creative vice president Michael de Plater told Eurogamer that this twist in the tale wasn't made simply to get an attractive lady into the marketing materials.
De Plater apparently considers Shelob and Gollum as "unsung heroes" of Lord of the Rings, Gollum because he's the one who actually (sorry, spoiler alert) destroys the ring and Shelob because she makes the deal with him that enables it to happen. He also said that Monolith draws inspiration from characters who exist in the story's "grey zone," because they're "more human" than the full-on good guys like Aragorn or Gandalf.
"So you've got Shelob representing darkness and then you've got Galadriel representing light, so you've got a duality between these two powerful women basically opposing each other in the same way that there's a lot of duality in our game," he said. "So we thought those two in opposition are really interesting, and the way Galadriel basically manipulated and sent people off on these different quests [testing the Fellowship with the mirror in Lothlórien] but ultimately left to themselves that quest [to destroy the ring] would have failed. Then you think of Shelob as almost the dark mirror to her, who actually had this minion that... if you think about it in a way, ultimately succeeded."
He also noted that while Shelob is evil, she's at least honest about it, unlike the guys who sent the Fellowship off on a quest that they knew was all but doomed right from the start.
As for exactly how she's able to change forms, Shelob's mother was Ungoliant, an evil spirit who took the form of a spider—and to de Plater's reckoning, it was her choice to take that form, and thus she can take other forms if she wishes. As her daughter, Shelob shares the same ability and can thus choose to assume other forms as well.
De Plater surely has a firmer grasp of Tolkien's tales than I do, but even so this seems like a real reach—almost like the decision to create Sexy Shelob was made and then a justification found, rather than the other way around. It's also a little hard to reconcile this shapeshifting ability with her great age and entirely spider-like behavior outside Shadow of War's narrative. Being a giant spider would no doubt come in handy at times, but would you want to spend centuries on end in that form if you didn't have to?
Anyway, there you have it: Shelob is an attractive lady in a slinky dress because she can be and wants to be, this one particular time. (Chris, meanwhile, informs me he prefers her in full-on spider form—he even married her that way in a Lord of the Rings mod for Crusader Kings 2.) Middle-earth: Shadow of War is set to come out on October 10.