There is an unused predecessor of what we know now Apparitions, which is called The Spectre, It has no legs only a wide trailing gown. (Model name is cameraco.BIN inside the obj.CRF archive) There is an unused plant in the games' files (TDP/TG and Thief 2 The Metal Age) called the Periscope Plant, it is similar to the Periscope Eye that was used in Cragslceft Prison, it is possible that it could have been a prototype for what we know now as the Eyeball Plant from Thief 2 The Metal Age, It has the appearance of a leafy outdoor plant with a long and thin central stalk on the end of which is periscope lens. The Original model based on concept art appeared in the Thief Gold's hidden mission Blooper Reel. These were replaced with the Green unsexed bugbeasts that you see in the game. Originally the bugbeasts (named Bugdemon) appear Female and pink skinned.
The file is a duplicate of the sounds in the English folder.
In Thief Gold, RES/snd.CRF has a folder GUARD2, which contains TEST.ZIP.
Each file within that subfolder is test audio that simply states what happened on a given bank, such as changing alert levels, being attacked, and so on. In The Dark Project, not Thief Gold, RES/snd.CRF is a compressed zip file, with a folder testvoic.