Gumroad - Body Mechanic Rigs Mega Pack 1.1 | 11MB
Here they are, all 12 of them! These Maya rigs are perfect for honing in on body mechanics and acting as you develop your character animation skills.
Here's a longer walk through, showing the key new features:
They will work with Maya 2014 and up, and come with an AnimSchool Picker that can be mapped to any of the rigs by changing the namespace within the picker ui.