What feats (if any) can turn Intimidate into a class skill?
You can also use Bully Breed (from horror adventures) to turn Intimidate into a class skill for your mount or animal companion.
Hermean Blood requires them to both use the same ability score, while Cosmopolitan requires them both to be Intelligence-, Wisdom-, or Charisma-based skills.
As mentioned by @Anne Aunyme, Additional Traits can grant you intimidate as a class skill depending on what trait you pick.
It's 3.5, but that's usable in many pathfinder games.