Arachne is a demon spider. She lives in The Room of Arachnids.
Arachne is a story told in Hyrule. It is said that she was once a beautiful woman who lived in Ancient Hyrule. She was extremely talented in weaving. One day, she fell in love with a man and she thought he loved her back, so they got married. The man cheated on her with another woman, and this enraged Arachne. She invited both of them to dinner at her house, and poisoned the woman that her husband had fornicated with. She then tied her husband to a wall in her house and cut him apart piece by piece, even after he was dead from blood loss. When her neighbors got worried the next day, they found the door to be unlocked, so they entered to make sure Arachne and the others were okay. All they saw was a giant demon spider. Arachne tied them up in spider webs and poisoned them. Her poison liquified their muscle tissues, so she could eat them (because spiders can't eat solid food). Arachne then fled and the demon spider was not seen again. Anyone who saw her afterwards was eaten.
The house that she lived in is called The House of Arachne. It is believed that the house is cursed and haunted by the people that she killed.