Arachne

Arachne (in Ancient Greek: ἀράχνη) was a great mortal weaver who was turned into a monster spider by Athena. Arachne's name simply means "spider" in Greek.

History
Arachne was the daughter of Idmon of Colophon, who was a famous wool dyer in Tyrian purple. She was a fine weaver in Hypaepa of Lydia. She was as skillful as the finest artist of the day and much praise was given to her in Hypaepa, where she had her workshop.

This all went to her head and eventually Arachne became so conceited of her skill as a weaver that she began claiming that her skill was greater than that of Athena, the goddess of wisdom, war ,arts, and weaving. Athena was angered, but gave Arachne a chance to redeem herself. Assuming the form of an old woman, she warned Arachne not to offend the gods. Arachne scoffed and wished for a weaving contest, so she could prove her skill. Athena dropped her disguise and the contest began.

Athena wove the scene of her victory over Poseidon that had inspired the people of Athens to name their city for her. According to Ovid's Latin narrative, Arachne's tapestry featured twenty-one episodes of the infidelity of the gods, disguised as animals. For example: Zeus being unfaithful with Leda, with Europa, and with Danaë, among others.

Even Athena admitted that Arachne's work was immaculate. Athena did win the contest, but she was so outraged that Arachne had disrespected the gods with the images in her tapestry, she turned Arachne into a spider. Some versions of the stories say that in fact Athena attacked Arachne, forcing her to hang herself in protest. In response, Athena covered Arachne in Helsbane, and allowing her to weave forever. Her name, Arachne, is closely linked with words like Arachnid and Arachnophobia.

The Lightning Thief
While Arachne is never seen it is shown several times that children of Athena have a mortal fear of Arachne's children, spiders (arachnophobia). Annabeth is so scared of spiders that she even has problems with anything that looks like them. When Ares sends Percy, Annabeth, and Grover to Waterland, they were attacked by tiny mechanical spiders made by Hephaestus. Later, when Annabeth is so entranced by a Sim City type game in The Lotus Hotel, Percy has to say the word "spider" to snap her out of her trance.

The Mark of Athena
Arachne appears as the final obstacle in Annabeth's way as she follows the Mark of Athena to the Athena Parthenos. The statue is kept in Arachne's chamber, which is covered with spiderwebs and Arachne's own woven tapestries. Arachne's tapestries, according to Annabeth, are the most beautiful she's ever seen (one of them depicts Percy and Annabeth's first underwater kiss, as if she'd been there watching them). Arachne is seen to be in collaboration with Ephialtes and Otis, who seem to fear her despite being immortal giants.

When Annabeth arrives in Arachne's chamber, the spider woman initially plans on eating her. Arachne tells Annabeth that she was a far better weaver then Athena and shows Annabeth her tapestries. Annabeth knows that she can not defeat Arachne in combat so she  uses Arachne's pride against her, luring her mother's nemesis into the idea that Annabeth, as Chief Architect of Olympus, could arrange for Arachne's work to be displayed on Mount Olympus, even in the Hall of the Gods itself. Annabeth tells Arachen that she is on her side and has always hated Athena, Annabeth promises that if they work together she can give Arachne a better reputation. Temptingly accept the offer Arachne agrees.However, she adds that Arachne will have to prove herself with a weaving challenge, and tricks Arachne into weaving monster-sized Chinese handcuff. Claiming she spots a flaw inside, Annabeth tricks Arachne into entering the Chinese handcuffs, whereupon Arachne is trapped.

However, after Annabeth taunts Arachne with the knowledge that the Athena Parthenos will be restored to Mount Olympus, and that Arachne has inadvertently helped Athena, Arachne becomes outraged and threatens Annabeth, the monster begins to bring down the entire chamber, opening a pit directly to Tartarus. Though Arachne falls down into the eternal darkness, she manages to ensnare Annabeth and drag her along to the edge of the pit. Percy grabs hold of Annabeth, but knows their friends will never be able to save them, and he himself cannot sever Arachne's silk, which is still bound around Annabeth's ankle. Charging Nico di Angelo to come and meet them at the Doors of Death, Percy lets go, and he and Annabeth fall with Arachne into Tartarus.