I have encountered this before where a complex object such as dragon has several mats for differing parts of the object (skin, eyes, claws etc).  If the object components are all grounped together and you select the object and then try to tweak the texture material, then the different textures associated with each part of the object are scrambled.

Try ungrouping the object or selecting the particular bodypart mesh you want to alter using the popup menu at bottom right and then just adjust the material/texture to your liking.

Hope this solves your problem.

Steve