Spider Queen

The Spider Queen is a very rare creature that only spawns at night. She visually looks like it's less dangerous and more common kin, Small Spider and Large Spider, but three times bigger.

In terms of combat, she will run away and likely disappear in the night if the player needs to run or hide to avoid dying after engaging her.

When close enough to the Spider Queen, a dark soundtrack will start to play and work as an indicator that the Queen is very close, and the player is hunted by her.

Combat
The Queen will be surrounded by small spiders, varying from 2 to 5 of them if the Queen is damaged. The spiders do very little damage, but will work as a distraction as well as poisons the player as the Queen does. If the player kills a spider, more will appear from under the queen.

The Queen delivers some mighty blows and does some extreme poison applying compared to all other spiders. Even though she does not have a lot of Health, she is extremely dangerous to new players. Poison Antidote is not very effective during combat, as the player will be poisoned after each strike the Queen delivers, so Strong Bandage and Health Potions are crucial.

Known drops

 * Spider Silk
 * Spider Guts
 * The Queen's Fang
 * Signet of the Alchemist
 * Spider Queen's Eye

Source

 * The Spider Queen (aka Spider Queen Quest)
 * A Song Of Vengeance (Composer quest)
 * Uninhabited Islands (at Night, very rare)

Trivia

 * Arnath's Journal explains about someone named Salin (also mentioned by the Innkeeper) who was obsessed with dark creatures, and also should have crafted the Signet of the Alchemist. Salin was never seen again probably because he was killed and eaten by the Spider Queen, therefore the ring is only obtained by killing her.
 * Killing the Spider Queen for the first time lets you complete the "Arachnophobia" Steam achievement.