FurAffinity - Fur Affinity, the internet's largest online furry art community.
PaintBerri - PaintBerri is a free art site that offers an awesome oekaki community.
DeviantArt - deviantART was created to entertain, inspire, and empower the artist in all of us.
okekai - A small community site where you can draw, animate, and chat through pictures all for free
ArtStation - ArtStation is the leading showcase platform for games, film, media & entertainment artists.
Brush Ninja - Hand-drawn Animated Gif Creator