Check out a huge set of IMM brushes by Michael Dunnam that can help you quickly get a base form of a monster. The set includes 94 parts in 9 IMM brushes.
This set is intended to be used as a base for sculpting. You will not get a finished model after you use these brushes, but they will still save you some time.
Don’t forget to visit Michael’s website to learn more about the XMD project and his recently released toolbox plugin for ZBrush.