Here is a quick post about a community that holds an animation contest every month.
They are called the '11 second club' and they provide a sound bite that is roughly 11 seconds
in length at the beginning of the month. And tons of animators from all around and from all different levels make animations in 2D or 3D! If you are ever out of exercises or things to do, the 11 second club is always a good place to go to motivate yourself or test yourself if you are an animator.