Deformers in Cinema4D are really powerful and flexible. I am learning them by doing mostly still compositions (except for the one animation below with the wind deformer).

 

I enjoyed building these, I hope you'll enjoy looking at them too!

This is a pretty useful deformer that can be used to create 'low poly' looks or to optimize models that have too many polygons and need to be optimized for faster rendering. The following is a very simple use of it on a sphere, showing the effect of progressively increasing the strength of the polygon reduction, to the point of getting a crystal-type shape.

This next composition uses the so called smoothing deformer with a fall-off. The fall-off basically lets you control how much (spatially), an effect applies. So here, from left to right, the smoothing of the platonic shape into a sphere is progressively applied from none to fully, with a 'sphere fall-off' that is coming from the left, starts impacting (smoothing) the left of the platonic shape until in encompasses it all and turns it into a sphere. The spiky polygons come from the low polygon count and are an artifact of the fall-off sphere. I liked the artifact as it created an interesting, rocket like shape...

The wind deformer is fun to play with. Typically used for a flag, it is used here to dynamically deform a  paper-like structure. I liked the resulting effect. It was hard to figure out how to create a looping animation with the wind deformer and finally found a thread that explained how to do it (at the very end).

 

If you watch carefully, you'll see the shadow dancing along with the morphing shape.

The formula deformer is pretty handy to apply a mathematical equation to geometry. Here, I used the manual mode to control the x, y and z coordinates individually with different formulas. 

Here, I wanted to build an effect where a low poly, rough geometry would refine itself into a perfect shape. After experimenting with the displacer deformer, I ended up creating a series of rendering for various basic shapes, using the same process. I used the deformer with a box fall-off to create the effect on the basic shapes. Then, I extruded the external, deformed shape after removing the top, non deformed part of the shape (see illustration below). Finally I created a slightly smaller, identical basic shape placed inside, and with a different shading. 

Below are a few other variations on the same theme.

Cinema 4D has a whole system for dynamics, which can be used to model cloth, but the collision deformer can also be used to create wrinkle effects similar to cloth (or to create all kinds of other deformations, like plastic deformations). Very simple use of that deformer in the following composition.

The collision deformer is pretty powerful and I experimented with it (see this project's work in progress), for effects such as this one, where the white, low-poly brackground is created from collision with the front pyramid.