Couple suggestions for your Outlaw rogue there, kind of depends on how Old God you want to go though 
Treachery’s Bite, Kilrak, Jaws of Terror or Horned Mace of the Old Ones could all work.
If you’re going Assassination or Subtlety and wanted daggers, you really can’t go wrong with Fanged Tentacle as Hroardane mentioned.
Mandible of the Old Ones or Spiritsever could also work.
Or if you want something a little bit creepier, Oregorger’s Acid-Etched Gutripper has an actual eyeball hanging off it 