This is not the best example that I have seen pictures of, but it is the only Lenticular (lens-shaped) cloud I have seen in real life. Have a look at this Wikipedia article for more info., sometimes they are even mistaken for U.F.O’s!
He loads the clouds with moisture,
and they flash with his lightning.
The clouds churn about at his direction.
They do whatever he commands throughout the earth.
(Larger version of photo on Flickr here.)