Make it a Karsite instead of an arctic kobold. Then, not only can they not cast spells, they have SR so other people can't buff them.
Yes, your base stats will be better, but who cares if your wisdom is higher if you can't cast spells?
EDIT: Honestly, a Karsite Metal Master 20 may come close to the worst druid. You have no animal companion, no wildshape, and no spells. Instead, you get Iron Body 1/day, Major Creation 1/day, and DR 5/adamantine. And some useless skill bonuses.
You have 3/4 BAB and proficiency w/ martial weapons, is about the only thing going for you.