Racial Ability Modifiers, can you check my math?

[sabelo2000]

For a one-off adventure my DM is allowing us to play nonstandard races, I've chosen the Grig (MM 235). As far as I can figure it, the entries in the MM have standard 10/11s in all ability scores, so my Grig's racial ability modifiers should be STR -6, DEX +8, CON +2, INT--, WIS +2 and CHA +4.

Have I done this right?

[GenericMook]

Yeah, although I'd change it to INT+0. More of a notation thing than anything else, but I was wondering why your DM was letting you play a creature that isn't sentient when I saw that.

[sabelo2000]

You know, you've just given me a horrible, yet wonderful, idea. One of the other players and I work immensely well together, I bet I could convince the DM to let me play a mindless undead thrall or vermin pet to my buddy.

By RAW, are mindless creatures ALLOWED to take class levels?

[tyckspoon]

By RAW, are mindless creatures ALLOWED to take class levels?

RAW may not strictly forbid it, inasmuch as it doesn't directly say "mindless creatures cannot advance by class"- I'd have to do some rather more detailed reading to be certain of it. RAI definitely says no- mindless creatures cannot learn, think, or remember. They have no skill points and no feats beyond racial bonuses. They automatically fail Int checks. It is difficult to conceive of how such a creature could take on class levels, which generally involve learning how to do something.

[Deaxsa]

Dont forget that all feats the marke with a b are bonus feats and the monter automatically acquires them, no matter what. in your case; of Dodge, Stealthy, and Weapon Finesse, Dodge and W.F. are both bonus feat you automatically get.
http://www.d20srd.org/srd/monsters/intro.htm#feats

Sometimes a creature has one or more bonus feats, marked with a superscript B (B). Creatures often do not have the prerequisites for a bonus feat. If this is so, the creature can still use the feat. If you wish to customize the creature with new feats, you can reassign its other feats, but not its bonus feats. A creature cannot have a feat that is not a bonus feat unless it has the feat’s prerequisites.

[Karnith]

By RAW, are mindless creatures ALLOWED to take class levels?
The SRD would indicate that they are not intended to, and there are no published monsters that I am aware of that are both mindless and advance by class levels.

The SRD has the following (http://www.d20srd.org/srd/improvingMonsters.htm) to say about monster advancement by class levels:

Intelligent creatures that are reasonably humanoid in shape most commonly advance by adding class levels. Creatures that fall into this category have an entry of "By character class" in their Advancement line. When a monster adds a class level, that level usually represents an increase in experience and learned skills and capabilities.
It also has this to say about advancing by HD:

Intelligent creatures that are not humanoid in shape, and nonintelligent monsters, can advance by increasing their Hit Dice. Creatures with increased Hit Dice are usually superior specimens of their race, bigger and more powerful than their run-of-the-mill fellows.
Since there are, to my knowledge, no mindless creatures with advancement by class level, mindless creatures do not advance by class level. You could create a monster that does, I suppose, but you would be going against all precedent.