Kobolds and Goblins have no LA and only 1 HD. When they take a class,
their class level replaces their HD.
Catfolk have a +1 LA and only 1 HD. Like Kobolds, Goblins, and the PHB races, their class determines their HD, but there's a catch: they start a level lower. In the case of a 2nd-level game, the PHB races will all be level 2, but the Catfolk will be level 1 because its racial abilities are more powerful.
Gnolls have a +1 LA and 2 racial HD, so a plain gnoll is treated as a 3rd-level character. If a creature has more than 1 racial HD, you can't replace those HD with class levels, which means you're stuck with them. Racial HD beyond the first are
generally a burden, in that they're inferior to class levels. Case in point: gnolls are CR 1 but they're treated as 3rd-level characters.
Edit: You could work out a progression for the Catfolk and Gnolls. Savage Species has a lot of examples (including a gnoll, I think); they essentially take "levels" in their "racial class", and have to finish it all the way until they're a full-grown version of the creature. Here's a sample progression, which I whipped up on the spot:
A 1st-level kobold sorceror, for instance, has a single d4 hit die, just like an elf, human, or halfling sorceror of the same level would. |
Catfolk have a +1 LA and only 1 HD. Like Kobolds, Goblins, and the PHB races, their class determines their HD, but there's a catch: they start a level lower. In the case of a 2nd-level game, the PHB races will all be level 2, but the Catfolk will be level 1 because its racial abilities are more powerful.
Gnolls have a +1 LA and 2 racial HD, so a plain gnoll is treated as a 3rd-level character. If a creature has more than 1 racial HD, you can't replace those HD with class levels, which means you're stuck with them. Racial HD beyond the first are
Most racial HD are like taking levels in the Warrior NPC class, which sucks. Dragons and Outsiders are the only things with racial HD that don't completely suck. |
Edit: You could work out a progression for the Catfolk and Gnolls. Savage Species has a lot of examples (including a gnoll, I think); they essentially take "levels" in their "racial class", and have to finish it all the way until they're a full-grown version of the creature. Here's a sample progression, which I whipped up on the spot: