When an object reaches the 100-year anniversary of its crafting, sometimes it forms an amalgam with a kami, creating a creature known as a tsukumogami. Tsukumogami run the gamut in personality, outlook, and function. Objects that are well kept and cared for often form curious and helpful tsukumogami. Most commonly, tsukumogami are mischievous and frightening but not actually malign. Tsukumogami formed from objects that have been abandoned, neglected, or misused are dangerous both to the humans around and to themselves, as their uncontrolled rage might eventually transform them into oni.
Pathfinder Roleplaying Game Bestiary 5 © 2015, Paizo Inc.; Authors: Dennis Baker, Jesse Benner, John Bennett, Logan Bonner, Creighton Broadhurst, Robert Brookes, Benjamin Bruck, Jason Bulmahn, Adam Daigle, Thurston Hillman, Eric Hindley, Joe Homes, James Jacobs, Amanda Hamon Kunz, Ben McFarland, Jason Nelson, Thom Phillips, Stephen Radney-MacFarland, Alistair Rigg, Alex Riggs, David N. Ross, Wes Schneider, David Schwartz, Mark Seifter, Mike Shel, James L. Sutter, and Linda Zayas-Palmer.