I'm slightly not sure if it's intended, but I've seen this one spawns with a bunch of other Troglodytes and fights against all of them, then against beetles. Seems like he's hostile to everything. I've only seen them spawn on the "Along the Scamandar" (if that's how the river is called). Was about few weeks ago though so I'm not sure if it's still a thing.
Pretty sure this isn't a bug, and just some crazy experiment slaughtering his own kind...:)