This is Hive Queen Aracne, the leader and 'queen' of a clan of unique creatures. Only females appear like this, while males look... less freaky and are far smaller. Much like spiders in real life with females being double the size of their male counterparts.

The Hive Queen of the clan (Such as Aracne here) rules over a hive made entirely of males, females are only born when a newborn larva is fed a special jelly like substance that works with the genetic gender codes and turns said larva into a female. Without the jelly all young born from the Hive Queen are male. They also have a hive mind like mentality, in that the queen gives the orders and her followers go through with them. Without a queen the hive and clan will die out.

Think of them as a giant bee/termite/ant clan in many ways just... with a giant spider queen that rules over them.

Inspiration for Hive Queen Aracne comes from two creatures in Dark Souls, Chaos Witch Quelaag and her sister. A pair of females fused onto the back of giant demonic spiders :) Aracne is a Bisharp/Galvantula combo if you couldn't tell.