The borg are maybe the closest Trek came to it, but after a while they started adding stuff here and there–some borg can become good, there’s a borg queen bee with a crush on Picard and maybe Data, 7 of 9. In the end, they made the borg too human-like.
To look at it another way, if Trek was to meet Predators, they might at first seem a lot like Klingons. But again, the Klingons became “civilized”, or maybe “Federationized”, as the story went on.
What would make Aliens or Predators work in Trek is that they don’t become “Federationized”, the aliens remain creatures devoted to finding faces to hug, and Predators remain apex hunters.