Johan The Dog is a free quadruped rig for Maya for use in non-commercial projects.
Johan The Dog
Grey Matter Gary
Grey Matter Gary is a free Maya rig from Squiggly Rigs
Rig – Azri (FREE)
The AZRI Rig is a simple animation rig for Maya 2018 and above, representative of video game projects aimed at retaining a high frame rate when working even on lower-end machines. Featured in the book, ‘Game Anim’
Red Dragon Rig
Red Dragon Rig is a free Maya rig made by junior rigger, Elise Mathez
Fantasy Crocodile Rig (FREE)
Fantasy Crocodile Rig is a free Maya rig that has a super appealing design.
Rocket Girl Rig (FREE)
Rocket Girl Rig is a free Maya rig from the VMComix animation blog.
Jasmine Rig (FREE)
Jasmine Rig is a free rig for Maya that has a load of great features!
Tre Vital Rigs (FREE)
Tri Vital has created a collection of awesome Maya rigs and put them on gumroad for free!
External World Rigs (FREE)
The External World Rigs are a free set of rigs for 65 characters created by David O’Reilly
Animator's Resource Kit 