Levelling monsters instead of advancing HD

[Patryn of Elvenshae]

I read the line "Often, intelligent creatures advance by gaining a level in a character class instead of just gaining a new Hit Die" as actually explaining the appearance of the "Advancement: By character class" descriptors. Personally, I only add character classes when it says so, just like that, in the monster description.

Whereas I (obviously given my above comments!) read that as, "A creature with 'Advancement: By Character Class' may *only* advance by character class."

 

[Terraism]

Well, the Gargoyle's favored class IS fighter (see "Gargoyles as characters"), so there's certainly no problem. However, it's wierd that this is the case, given it's propensity for hiding and its Freeze ability. I'm surprised it's not a Rogue focused creature. That said, dropping 2 levels of Rogue onto Gargoyles for a +1 CR is certainly an interesting prospect.

Like Frank said, rogue is almost certainly an associated class for gargoyles, regarding levels and CR boosts. As far as favoured class is concerned, remember that it's not always chosen based on what makes the best mechanical fit, but instead based on racial propensity. Obviously, the designers felt that those gargoyles unique enough to take character levels had a strong tendency towards direct violence, represented in the fighter class.