I've killed all of the BOBs except Lone Wolf on Legendary, and almost all of them in a no death run of their level, and you don't get anything. Check out the BOB index if you want proof:
http://halo.bungie.org/misc/thebobindex.html
This is probably another thing that Bungie wanted to include in the game, but had to partially scrap to make their release date; like Halo 2's skulls, it seems that BOBs were not fully implemented.
English
-
I hate you
-
Man you put a lot of effort into this. I commend you and Thank You. "LIKE" "FOLLOWED"
-
Thank you!
-
I thought there might be at least an Achievement for eliminating all the BOBs. Maybe even unlock some special armor from Waypoint.
-
That might have been the original intent; I get the impression, however, that 343 has no idea what the BOBs are all about, so I doubt it was ever tied to Waypoint. In any case, it was Luke Smith's idea (allegedly) so he'd be the one to reveal the secret, if that were to ever happen.