Arachne's Keeper

Arachne's Keeper is a  spawned in the Spider's Den. It has. It spawns naturally in the Spider Cave under the Spider's Den. When killed, it drops a Arachne Keeper Fragment. The Arachne's Keeper also has the ability to dash, leave a trail of webs, and inflict a poison debuff.

Strategies
The Arachne's Keeper can easily kill you if you aren't careful enough. If you want to avoid its attacks, try to attack it when it's against a wall or be on an elevated platform. (i.e. the mushrooms.) Make sure to avoid its webs as much as possible.