I know the original post is old (from december!), but...
The Boss and Underling dialogue can be seen at the Sewer Access (of course), but also at the Black Omen. The first time you fight your way through the Black Omen in each of the 12000 BC, 600 AD, and 1000 AD eras and get to the room where the two nus are, talk to one of the nus who asks you if you want to stay dreaming or wake up (or something like that- i don't remember), tell it you want to wake up. the boss and underling come out from off screen pushing a large platform-on-wheels thing, and they say different things to each other depending upon which era you are in, then tell you to 'get on, gribbit' or some such. I can't remember if the Black Omen is in 65000000 BC or not (I don't think it is, though), but the Boss and Underling are in every era except 1999 AD and the End of Time:
12000 BC, 600 AD, and 1000 AD they are in the Black Omen, and in 2300 AD, they are in the Sewer Access (because you can't get into the Black Omen). The Black Omen dialogue you found is all of the little bits of dialogue from each of the Black Omen eras put together. Just a bit of useless information...
[1000 AD]
UNDERLING: You're starting to bug me!
How long do I have to put up with
your drivel, ribbit?
BOSS: Just shut up and push, will ya,
GRIBBIT!
[600 AD]
UNDERLING: Hey, Boss.
What's your life's dream, ribbit?
BOSS: My personal dream?
To be King of the Sewer!
Gribbit!
[12000 BC]
BOSS: Oh, all right...!
What's your little dream?
Gribbit.
$8SK2:
UNDERLING: I just want to keep being
your apprentice, ribbit.
$8SK4:
BOSS: Sheesh!
You're making me cry, here.
[pause]
I'm gonna tell Krawlie what you just
said!!
I don't remember what the Boss and Underling said in the Sewer Access, but see how all the Black Omen dialogue from each era sort of matches up? (Like one whole conversation?) Does the Sewer Access dialogue fit in with the Black Omen dialogue continuity also, I wonder?
Also, Krawlie is mentioned (see above) in the 12000 BC era at the Black Omen, but the only time we meet Sir Krawlie is in 2300 AD. So, does that mean Krawlie is originally from the 12000 BC era? If so, how did he get from the past to the future? Was he also on the Black Omen? Or does it really matter what era Boss, Underling, and Krawlie are from since the Black Omen is supposed to be separate from time (or something like that)? Is there any significance at all in this? Should i even CARE?! (am i over-analyzing???)
...