Arachne's Brood

Arachne's Brood is a mob spawned in waves by Arachne when she falls below 50% and 25% of her health, similar to the Sven Packmaster Tier 3 or above. They have 10,000 when Arachne is spawned with 4 Arachne's Keeper Fragments, or 100,000  when Arachne is spawned with an Arachne Crystal.