Source: Bestiary 5, pg(s). 253
An object that becomes a tsukumogami grows additional features such as a tongue, arms, or legs.
Tsukumogami run the gamut in personality, outlook and function. Most tsukumogami are not evil, but mischievous and scary. Benevolent tsukumogami form from well-kept and cared objects; while neglected or misused objects often form evil tsukumogami that are prone to transforming into oni. A tsukumogami is always merged with its ward, and unlike most kami, it forms an amalgam with its ward, so it can move and communicate while merged.