|Yeah, that's the one.|
A BOB is, as I mentioned, an Easter Egg. They have no real in game or in universe explanation. They are just a random special thing in the game for people to spend extra time hunting for. I had run across this one before, and after looking into it, I realized he was one of the easiest ones to find. Since I had never followed him, I decided to give it a try.
He was one tough hombre. His shield strength, per the wiki, is equal to an Elite General (the gold ones), but that is only half the story, since he was also the dodgiest fool to ever grace the normal difficulty level. And he was armed with that bane of Mjolnir; dual plasma rifles. But it the end, I prevailed. He showed up in the infantry carnage report as an 'Elite Light Vehicle,' which I had never seen before, and unlocked my 'Seek and Destroy' achievement.
I am so proud of myself.