The cave teuthopin replaced its ancestor in the Yannick Ice Caves. They have specialized in eating cave swarmers, catching them with their long, tridigital hand tentacles, though they also eat tunneling uksips if there are no swarmers around. Their 'feet' tentacles have grown longer to improve its movement. It moves by holding on to the cave walls and floor and pulling itself forward along the slippery ice. If necessary they can also 'walk' on their tentacles but this is not as fast. They lost their ability to change colors and are now an almost transparent, very light shade of blue. Their eyes have adapted to the darkness in the cave and can now also each look to a different side.
Cave teuthopins live in social groups of up to 20 members. Their primary means of communication is still via the vocal sac on the forehead. Teuthopins can sense vibration through their skin, but they don't necessarily 'hear'. They will use these signals to warn the others for danger, or to tell them where a large group of swarmers can be found. Because of their long tentacles, they can silently sneak towards an unsuspecting swarmer before snatching it out of the water.
The cave teuthopin still reproduces in more or less the same way as it's ancestors. The hermaphrodites fertilize each other's eggs, then place them in the pouch of a carrier. The young hatch inside the pouch, but are kept inside until they can survive outside. Even then they need much attention, being only a tenth of their parents' size. The group works together in defending and feeding the babies, who will reach their full size in about half a year.