Is there any kind of technical term (and if not, can you think of one) for a civilization that “eats” others to gain their knowledge, powers, etc.? Such as… the Borg from Star Trek sort of did this, or at least they said they were going to during their “You will be assimilated” spiel—their commitment to actually doing so seemed to vary depending on the writer. The Krillitanes from Doctor Who were said to do this, (“They would ‘cherry-pick’ the best bits from the people they destroyed.”) and in Warhammer 40,000, the Kroot and the Tyranids both do it… and in real life, it was believed for awhile that planarian flatworms could basically do this, too.
So in my tabletop RPG setting I'm writing, there is a civilization that does this big-time, and I'm just wondering if there's any kind of specific cool term or descriptor I could use to describe this trait of the civilization (not the action!), as opposed to just simply describing it, or maybe coining my own term?