Originally Probing the Membrane of Science
As objects are used and passed down the generations, they slowly accumulate fragments of a soul – little pieces of personality here, some quirks there. After a sufficient time, such as a hundred years or more, that spirit may become so powerful as to cause the object to animate. These are the tsukumogami. The attitude of tsukumogami depends on their type and the circumstances of their creation. A beloved heirloom that it tended well may form a benevolent spirit and protect its family from dangers. A battered and abandoned object may grow resentful and turn to pranks or even violence.
All tsukumogami are constructs with the following special abilities
Haunted (Su) A tsukumogami is treated as undead for the purposes of positive and negative energy. Any spell or effect that has special effects when used against the undead affects tsukumogami as if they were undead as well.
Soul-Powered (Su) A tsukumogami adds its Charisma modifier to hit points for every Hit Die it has.