The working idea so far is ‘creatures designed to be guardians of some other species, find themselves with humans as wards instead, don’t quite understand what a human would percieve as Silly And Nonthreatening’
There’s a subplot about the world/dimension they’re from being a casualty of war - some of the surviving HITHEREs being untainted and some being victims of a type of eldritch rabies that causes them to abandon their nurture/protect programming in Quite Spectacular Ways
some advanced symptoms of the “eldritch rabies” include those bulging eye veins (“veins”) and nerve/wormlike tendrils poking thru the pupil/iris. Particularly advanced infections probably see these things shambling around with tendrils pouring from eyes mouth ears, et cetera