51 Animation Exercises is a list of exercise ideas that can be used when you are unsure of what to animate. Whether you’ve animated a bouncing ball or not, this list will have something to keep your skills sharp. Compiled by Animator Island
BOTW Zelda Rig is a free Maya rig based on the Breath Of The Wild version of Zelda. Made by Christoph Schoch.
The Zelda Rig is a free Maya rig made by Christoph Schoch and is available on his Gumroad page
The Link Rig is a free Maya rig made by Christoph Schoch and is available on his Gumroad page
Grease Pencil Rigs are a free set of basic rigs for Blender 2.8 that are for use with Grease Pencil. They are aimed to ease the drawing of characters by showing construction lines which you can use for reference while drawing.
Johan The Dog is a free quadruped rig for Maya for use in non-commercial projects.
Advanced Skeleton has been used to rig creatures, props, vehicles and just about anything since 1999. It is free to download but if you want to use it for a commercial project you will have to buy a license.