I witnessed another dropped PC Properties skin this morning, in the first spawn of giants in the Forest Giant Cave.
Skin title/description: (for some reason my screenshots haven't been saving properly)
PC Properties
This item is used for Expansion Pack 3 (1.69) to store PC properties used by horse scripts.
Base Item: Creature Item
Weight: 0.1
This item was dropped by a Forest Giant Feller, as opposed to one of the stalkers, if it matters.
Approximate time of event: 11:20 am PDT, Sept. 16, 2008