I’m done with my sculpting and am wondering wat is the best way to rig to open and close this claw. First time in zbrush and rigging.
Thanks in advance for teaching 
I don´t think is possible to use Zspheres to rigg a claw. But you can create a polygroup for the under claw and then use the masking and transpose tools for posing.
That looks like 2 subtools. You can use a zsphere armature to rig it. Make your rig and then in the rigging panel select the mesh and then bind mesh(after you have selected your claw).
4z4r : Yea I think I gotta mask them and and use transpose.
Doug : Oh, they’re of the same subtool. 
Try a ZSphere rig(armature) just pretend it’s a mouth.