[mabmoro]

The villain of the campaign is actually not related to the dungeons origins, he's an evil transmuter who moved in some time ago, and started doing experiments on some of the hapless adventurers that stumbled in. Most of the TF-causing things in the dungeon would be left over from the time where it was controlled by the nature-lovers. Two examples of things that I've placed in already:

1. Robes and stylized animal masks. Used in ceremonies to 'commune with the beast mind', when the robes and mask are worn simultaniously, a second, subordinate mind awakens in the wearer's. This mind is purely animalistic, specific species dependant on the specific mask. The wearer can draw upon instincts and skills, but is at no risk of the animal taking over. However, if just the mask is worn, the animal mind takes over fully. No physical changes are caused directly by the mask, and theres nothing keeping it stuck to the PC.

2. Dead end traps. In every dead end, theres a rune that when approached within 5 feet, will cause people within said dead end to incrimentally change into an animal. This trap existed when the dungeon was active, since its safe to assume that only intruders would venture into a dead end.