Reference:


Hide the tail and make the ball first,
Set the animation length to about 80 frames
Do up and down bounces first
0 , 4 0 , 6 0 , 8 0 frames with the ball on the ground
Set 10 , 30 , 50 , 70 frames for the ball to hang in the air

Adjust motion curves like this

The shape becomes longer when it bounces
After deformation, the motion curve changes to this (loop)

Tail Part

Final Work