The Gaming Den

If you are thinking of going Rogue, you might want to pull in the Lords of Madness rulebook for access to the Darkstaker feat. That's to prevent creatures with blindsight, tremorsense, etc from auto-detecting you.

You would also want access to the Hide in Plain Sight class ability. With LoM and Core being your two books, you'd either have to eat a level of Shadowdancer or 8 levels of assassin (which at least gives you you full sneak attack progression and the occasional non-craptastic spell). They are both not-very-good PrC's, but HiPS is kind of a vital ability for any stealthy character.

LoM has a bunch of PrC options in it, but I didn't see anything I though would really be great for a rogue-type character. Maybe someone will spot something I didn't.

If a worg or it's ilk is key to the concept, you could try the feat animal companion.

You can even take it at first level.