Bandai Namco have generously released their BNS Rig for Maya for free. Based on the one used throughout their Tekken and Soul Calibur series, the rig is very simple and low-poly so runs lighting-fast.
See below for license info:
- Can be used for non-commercial purposes only.
- Please make use of animation production practice, demo reel production in job hunting, and education.
- You are free to modify the model.
- Secondary distribution is prohibited.
Download the rig from their site (google translated) here.