2. Divide the model to a higher mesh resolution (Tool/Geometry/Divide) and do the sculpting with Zbrush brushes.
Beside the known sculpting tools you can use other textures as a stencil. Creating a stencil: import the texture you want to use as an alpha (Alpha/Import), then set it up as a stencil (Alpha/Make St). Under the Stencil palette you can parameter the stencil and with holding down Space bar you can move and rotate it using a Controller..
Using Wrap Mode you canproject the stencil onto the sculpted surface.
Enable LazyMouse(Stroke/Lazy Mouse) for precise smooth drawing, which is needed for creating thesmooth creases.
Form the skin'spores and the surface of the chitin using DragRect Stroke and ZBrush Alpha07.