Cavern Terror

The caverns were a Corrupted Terror's territory. 

A Corrupted Terror… it had not been that long ago that Sunny would have shuddered from a mere thought of fighting a creature like that. He was still apprehensive, of course, but not nearly as much as a wise person would have been. 

An abomination of that Rank and Class was not something a lone Master should have the ambition to kill — or a cohort of them, really. Sybil of the Fallen Grace, for example, had not only wiped out the entirety of LO49 and the enormous battleship sent to rescue its personnel, but also almost ended the lives of Sunny, Naeve, and Saint Bloodwave at Falcon Scott. 

A Corrupted Terror was a walking disaster of chilling proportions.