"Humanoid" Aliens get all the attention, but they also need all the same resources and environments as humans. so there potential competition. the Gell on the other hand could colonize 70% of the earth and no one would likely ever see one. living well over a mile deep in ocean pressure and temperatures close to zero these intelligent relatives of https://en.wikipedia.org/wiki/Rhizostoma_pulmo communicate via bioluminescence and don't even have a concept of conflict.