The aquatic earback split from its ancestor and adapted to a fully aquatic lifestyle. Because of this, it could spread to the Yokto Water Table. Its eyes have almost completely disappeared, but its other senses have improved. It has also developed the ability to fold up its back ears. This way it can swim faster, but it will only swim a short distance before folding out its ears again, to listen where it's going.
When hunting cavamari and ylbershpelle bubblehorns, the aquatic earback will first orientate using its back ears to listen for splashes and the tiny hairs on its tail to feel for movement in the water. It will then decide on a direction, fold up its ears, quickly swim a few meters and orientate again. This hunting method works fine because their prey can't move very fast.
The aquatic earback will make its home in crevices on the floor and walls of the caverns. It will also lay its soft, frog-like eggs there. They are not social at all and only meet during mating season. If two earbacks choose the same spot for hunting, they will try to scare each other off. Usually the bigger, more aggressive one will win.