Rigging of Slime

I found a tutor which is similar to what I need to rig the slime.

Ref link: https://www.youtube.com/watch?v=qcXZ6qCKV70

(Maya Rigging Tutorial for Beginners - Stretch and Squash rig to do Bouncing ball in Autodesk Maya)

After following the tutorial, I got this result which is not what I want.

Then, I add one more controller to hold the position of the bottom part of the body. It can make the animation have more variation.