Negative levels, among other things, give the following effect: "The creature is also treated as one level lower for the purpose of level-dependent variables (such as spellcasting) for each negative level possessed."
It's clear how this affects things with class levels, but what about monsters that only have racial hit dice. If a monster has an ability, like Stench, with a DC in the form of 10 + 1/2 HD + Stat Modifier, and then takes negative levels, does the DC go down for every 2 negative levels the monster takes? Does it matter if the original creature has an even or odd number of racial HD?
