Quote Originally Posted by Yora View Post
Q4: Does anyone know how many HD a 2nd level kuo-toa cleric or a 3rd level frost giant has? Both examples appear frequently, but to my knowledge there never where any rules for it. Has anyone heard something different?
A4: This is not clearly explained anywhere, it is true. The way I read it is that the minimum HD any creature has it what is indicated by the monster entry in the book, and any class levels at or below that level to not add any HD (though it will increase the XP award for the creature because of special class abilities). Class levels above the normal HD for the base creature add HD appropriately. Levels are only mentioned when the creature has class abilities: it's never just a 2nd level kuo toa, it's always a 2nd level kuo toa cleric, assassin, whatever.

examples - A 3rd level frost giant shaman has the normal 10HD for frost giants, but can cast 1st and 2nd level cleric spells from the shaman list.
A 2nd level kuo toa assassin has 2HD like all kuo toa, with appropriate thief and assassin abilities.

Also note, in the adventures where you see this sort of thing (GDQ, mainly), they say things like "Frost Giant Jarl fights as a Fire Giant" when they want to make a stronger Frost Giant, rather than saying he is a "level 2 frost giant chieftain" or "level 11 frost giant". Since the maximum level of shaman or witch doctor for any creature is 7th, there will never be a giant with extra HD from class levels.

Kuo Toa and Drow, on the other hand, are almost always found with class levels exceeding that of the base monster entry. I believe this is because they were designed specifically for the GDQ modules as threats for high level characters. There are very few other types of monsters written this way, with class levels and HD advancement, Githyanki and Githzerai are the only others I can think of right now, also very high level threats.