Squash and stretch effect by remapping the point positions along each axis. We take the input coordinates and redistribute the distribution along each axis.
One method with a spline ramp which is a nice way to 'sculpt' the deformation visually.
Another method uses bias() and gain() driven by sin() and cos() to cycle the distortions over time.
Also included are some 2D applications of the effect which produce some really pleasing designs.
Some nice explanation of bias and gain functions (invented by Ken Perlin) can be found here: https://blog.demofox.org/2012/09/24/bias-and-gain-are-your-friend/