Make character body elastic when is moving and jumping

I want my character to feel elastic like a slime when moves and jump. I was wondering if the tween extension or some x scale action lets the character back expand (-x). I tried a few, but they scale positive and negative.

Oh, is there a code for that? I don’t know to code. I can use it in custom extension right?

Tween yes

Same thing. Doesn’t work.

I want to just stretch the character -x, not positive.

If positive is x10 then negative would be x-10

Or maybe describe exactly how you would want your player to behave

Cause if we are talking about like a balloon squeezed from the top to the ground
Then you are confusing using 1 tween with 2 tweens

You need to squeeze it vertically but expand it horizontally
Press space to jump

I want my character to feel elastic like a slime/blob when moves and jump. That is, that the back of the ball stretch like liquid. But when I use tween, it stretch the character both sides.

I don’t want my character stretch on positive scale, only the negative one.