Kruthiks were reptilian hunters that form a hive of their own underneath the Araneum. They use their superior numbers to overwhelm and invade the Hive and other nearby creatures.
Some Kruthiks butcher their kills and carry them back to their territory for unknown reasons. One it could be that they were feeding their Queen, or simply they showcase it as their trophy.
According to Otik, he saw one of the Kruthik carry the skull of its prey and held it up high midair with a scream.
These underground hunters crawl in four spikey limbs. Their faces were like human-skulls of thick outer shells. These outer shells were like stones in nature, and some spikes sprouted their bodies.
To carry their prey without harming them totally, Kruthik's forearms were set in a toxic liquid. Incapacitating its prey.
"I haven't seen them on the surface," Ned said after listening to Otik.
"Well, that's because we stood in between you humans and the Kruthiks."