The greim has furthered its ancestor the laminato's predatory lifestyle. The strength of the muscles for swimming has increased. Many parts of its body have additional segments from duplication which helps in maneuvering. Such parts include the larger jaws, grabbing antenna, fins, and tail. A duplication of the jaws has also occurred, but these jaws are smaller and closer to the mouth. These are meant for food manipulation. What was once the radula is a sort of lower lip tongue structure which also developed plating. The outer portion of the tail segments have flattened out further into fins, while the center stays rounder due to the increased muscles. The grabbing antenna's sticky grasping area has increased in size to better hold on to prey it captures. The eyes of the greim are slightly better at seeing shapes and now can vaguely see color.

Its hunting style is uniform amongst its prey. It will patrol the crystal flora in search of prey. Once spotted the greim quickly swims toward the prey and use its grabbing antenna to either grab the prey or close distance with it. Once in the grabbing antenna's sticky bristles, the antenna will pass the prey to the larger jaws to the smaller jaws then the radula armed mouth.

The greim reproduces just like its ancestor. Mating is typically done in hollowed-out crystal flora, where organisms are least likely to disturb the eggs.