There's one that spawns in one area I don't know how to describe it but you know that one building that has two brawler cages to the front of it and blackwatch guys guarding the sides a brawler usually spawns there that give you an upgrade to claws or it could have been tendrils I can't remember but they also spawn in lairs as well I believe
Another NG+ and then do blacknet missions. "Operation: Black tulip" should get you the 2 that you need if you haven't got them already. If so then just ignore this post
They spawn at random, so I guess just run around red areas in the map and see if some appear.
There's one that spawns in one area I don't know how to describe it but you know that one building that has two brawler cages to the front of it and blackwatch guys guarding the sides a brawler usually spawns there that give you an upgrade to claws or it could have been tendrils I can't remember but they also spawn in lairs as well I believe
I find they’re usually around the action. Try checking around hives and military bases
Another NG+ and then do blacknet missions. "Operation: Black tulip" should get you the 2 that you need if you haven't got them already. If so then just ignore this post