So I've been through the game now, through the Prologue a few times, and I'm 99% sure this is just the remnant of an unimplemented quest, but I have to ask:

The Temerian Recruit at the bottom of the slope when you leave the tent you share with Triss, the only guard between you and the Crinfrid Reavers, will give Geralt something on the order of a hundred orens if you click on the "Job done" line, and when you do he makes mention of there being sewers and a cockatrice. Just having been fooling around with Triss (or trying to when that guard dropped by) it seems clear that I, at least, didn't have anything to do with killing any sort of beastie...

I'd like to think I'm thorough enough that I'd have noticed an entire hidden sewer complex in the prologue, but there are so many neat little things to see in this game that I just have to ask.

This IS a quest that didn't quite make it into the game, right? Thanks for any clarification.

coacktriace in witcher 2 ? .. r u sure ? .. i didnt see any ..

in witcher 1 ... u had to kill a cocktrice to get out of the jail

Nope, its from the first game. You had to kill a cockatrice. I'm assuming if you did it, you get this dialogue option. (I actually think you were forced to do it in TW1)

It's both a way to start Geralt off with money in his pocket and an in-game introduction to his profession for new players who might not really know the distinction between witcher and mercenary, especially since he's stomping around an army camp. It's also a sly little reference to his first monster job in Vizima (Foltest's capital city) in the first game. It's not a quest that you play in TW2, so don't worry that you're missing content.

Played the first Witcher game a few years ago so I was already familiar with [i]that[i/] cockatrice, but when that Temerian Recruit opened up his dialogue with a reward, it just got me wondering is all.

Also, being familiar with both Geralt's profession and with how frequently things get cut from games (and yet still have little remnants remaining in the finished product), it never crossed my mind that this one would have been deliberate.

Thanks for clearing that up.

PS. I also encountered the merchant in the Vizima Outskirts that you mentioned. That encounter made it much clearer that the orens were in payment for something that had already been taken care of, though; I found this instance a little more ambiguous.

Think it's there to give new players a bit of a feel for what Geralt does for a living, so it's not a missing quest obviously.