Oxide Queen

Overview
A mature rust monster which fed their equivalent of royal jelly shortly after birth or the first of a colony created by spontaneous generation, Oxide Queens are rare subterranean creatures which spawn more rust monsters ad infinitum. Capable of hibernation, they produce booms of rust monsters wherever there are abandoned mines or other excavated sources of steel. Spontaneously created, they can strip an ore vein in a matter of days. However, the noise and activity of nearby work causes them to retreat into deep nests and hibernate with their offspring for years, even decades. While rust monsters are typically solitary creatures, Oxide Queens are able to organize them into hivelike social hierarchies, similar to gigantic metal-consuming ants.

Specific Encounters
An oxide queen created a nest in the Ironhost Mine. After the Brass Boars disrupted mining operations in the town, she gained the opportunity to reproduce en masse. She can be found in a 30' radius chamber with 15' ceilings, surrounded on all sides by the hibernating egg-sacs of her children. Feeding off the bones and hoard of the silver dragon there, she battles parties alongside 5 rust monsters and 3 berserk silver dragon wyrmlings who have been driven mad by the rust monsters draining their regenerating eggshells. If imperiled, she will sacrifice many stored eggs to give live birth to more rust monsters to aid her in battle.