Arachne

Arachne is a boss spawned in the Spider's den. She has, but can spawn as a Runic variant. She can be summoned with 4 Arachne's Keeper Fragments, similar to Dragon fights. This can be done at the altar made of endstone and sandstone located at -282 49 -178. She can summon cobwebs and Arachne's broods, which have. Her drops include Soul Strings, Arachne Fragments, Dark Queen's Soul Drop and Tarantula Pets. Mage weapons do not work against her, similarly to Ghosts and the Sven Packmaster.

Summoning
To summon the boss, one must place four Arachne Keeper Fragments on the altar. After around a minute or so, the spider will spawn, saying a line of dialogue explaining how much of a mistake the players have made.

Behavior
After it spawns, Arachne will run around, damaging players around it. Wherever it walks, it leaves a large wall of cobwebs behind it, slowing down players that touch it. It is recommended to use an Aspect of the End to escape upon noticing your hindered movement.

At certain health intervals (info needed) it will summon a crowd of Arachne's Keepers which act similarly to Sven Pups. These spiders are also immune to magic damage.

Trivia
This is based off the Greek myth of Arachne, a spider-woman, who challenged the goddess Athena to a weaving contest.