The Morpheus Rig is a free Maya rig created by Josh Burton available to download from his personal website
Morpheus Rig v1.0 (FREE)
Minion Rig (FREE)
The Minion Rig is a free Maya rig based on the popular Minion characters from ‘Despicable Me’
Pink Panther Rig (FREE)
The Pink Panther Rig is a free character rig for Maya based on the popular character ‘Pink Panther’
Ultimate Rigs (FREE)
The Ultimate Rigs are great free Maya rigs for practicing body mechanics
The Fighters Generation
The Fighters Generation is a world renowned character database… featuring just about every fighting game character in existence. It boasts an unparalleled collection of the best quality artwork, pictures & animations!
Graph Editor Redux
Graph Editor Redux is a redesign of Maya’s curve editor toolset. Not only does it reorganize the classic graph editor functions, it provides new tools that many animators have found extremely helpful in massaging animation performances.
Cartoon Network D.O.C
Cartoon Network D.O.C is an amazing site for viewing storyboards, model sheets, backgrounds and more from cartoon network shows.
Iamag.co
Iamag.co is a huge collection of references for walk cycles. The collection contains illustrations, sketches, model sheets and tutorials…
Brendan Body (Birds)
Brendan Body has a great post on his website which displays lots of great reference and observations on birds and flight.
Animator's Resource Kit 