Those who study monsters posit that umonlees are related to chuuls, as the creatures exhibit some similarities. Both are semi-intelligent, crustacean predators that use ambush tactics to kill and eat their prey. Even though they can talk, umonlees typically only speak Aklo, which also gives credence to this theory. This would also lend to the theory that chuuls are products of alghollthu manipulation, meaning that umonlees are also the results of these alien designs. However, the fact that these creatures aren't evil argues well against such a theory.