Reference
In this video I can observe the motion of squirrel’s tail.
Planning
Processing
To animate the tail, start by imagining how it should move, usually with a smooth, wave-like swing. Set keyframes on the timeline for key positions, like the starting point, up position, and the opposite side. Adjust the timing between these points for a quick, natural rhythm. At each keyframe, adjust the tail’s position to create the swinging motion, beginning with the tail down, moving it up, and then to the other side. Add a slight delay between each part of the tail to make it look more wave-like. Finally, play the animation and make small adjustments to the keyframes and timing until the tail swings smoothly and naturally.