You can get the Bone trait in Dungeon Village 2 in your city by building Demon Castle, Fresh Milk or Mellow Cheese and taming Skelefish or Skelerina as pets. Worth 10 points each, Skelefish, Skelerina, Ghoulash and Fleetleek are the most points for acquiring the Bone trait.
The Bone trait is a requirement for one titles, including Rough & Ready Town.
The precise contribution of points for each factor in the Bone trait is listed below.