Who is a Bookworm?

At the Hellsong Tavern, one can hear many stories from demons. But the most remarkable of all is the story of the demon Daren, who managed to find the ancient library of Irman, Vagrot's right—hand man. Together with his faithful friend Malik, he explored the mountains to the north and found a passage that led them to the library.
 
The comrades explored an unusual place and turned into the section of combat grimoires. They expected to find scrolls or books that would help bring down meteorites on enemies. But instead they saw him—a worm whose body consisted of thousands of intertwined roots. He wasn't crawling. He rolled, rustling the pages, like a living encyclopedia of rage.
 
The worm attacked the demons, and they fled. But when the comrades reached the chronicle department, the beast stopped chasing. It was then that Daren realized that the monster did not want to kill them. He only guards his sector. Surely the library itself raises such guardians from dusty volumes. And this was only the first monster the demons had encountered.